Golang program to calculate the volume and area of a Cone

In this tutorial, we will be discussing the approach to calculate the volume and area of a cone using its height and radius in Golang programming.

But before writing the code for this, let?s briefly discuss the cone and its volume and area.

Cone

A cone is a three-dimensional figure that is pointed at the top and its base is flat and curved. The height of the cone is denoted by ?h? and the radius of the flat curved surface is denoted by ?r?. An ice cream cone is a good example of a cone.

$$\mathrm{where\: length \, =\, \sqrt{(r^{2} + h^{2}))}}$$

Volume of a cone

The capacity or amount of space a cone occupies is termed its volume. Calculating the volume of a cone can be beneficial in situations where we want to know how much ice cream we can fill in a cone.

$$\mathrm{Volume = (1/3) \ast \pi \ast (r)^{2} \ast h}$$

Area of a cone

The total area occupied by the cone is known as the surface area of the cone.

$$\mathrm{Area \, =\, \pi \ast r \ast (r+l) }$$

$$\mathrm{where\: l \, =\, \sqrt{(r^{2} + h^{2}))}}$$

Example

• Height = 7, Radius = 5

  Volume of cone = 183.33333333333331

  Area of cone = 213.75082562495555

Explanation

• Volume of cone = (?) * ? * (r)²* h

  = (?) * (22/7) * (5*5) * 7

  = 183.33333333333331

• For the area of the cone, first calculate the value of ?l?

  Length ?l? = ?(r² + h²))

  = ?(5² + 7²))

  = 8.602

  Now putting the value of ?l? in the formula for area of the cone-

  Area of cone =?* r * (r + l)

  = (22/7) * 5 * (5 + 8.602)

  = 213.75082562495555

Calculating the volume and area of a cone

Algorithm

Step 1 ? Declare a variable for storing the height of the cone- ?h?.

Step 2 ? Declare a variable for storing the radius of the cone- ?r?.

Step 3 ? Declare two variables for storing the area of the cone- ?area? and volume of the cone- ?volume? and initialize both the variables with the value 0.

Step 4 ? Calculate the volume using the formula- Volume = ? * (r)² * h, and store it in the ?volume? variable in the function calculateVolumeOfCone().

Step 5 ? Calculate the value of ?l? using ?(r² + h²)) so that it can be used in the formula for the area of the cone.

Step 6 ? Calculate the area using the formula- Area = ? * r * (r + l), and store it in the ?area? variable in the function calculateAreaOfCone().

Step 7 ? Print the calculated volume and area of the cone, i.e, the value stored in the ?volume? and ?area? variables

Example

<div class="execute"></div><div class="code-mirror  language-java" contenteditable="plaintext-only" spellcheck="false" style="outline: none; overflow-wrap: break-word; overflow-y: auto; white-space: pre-wrap;"><span class="token keyword">package</span> <span class="token namespace">main</span>

<span class="token comment">// fmt package allows us to print formatted strings</span>
<span class="token keyword">import</span> <span class="token punctuation">(</span>
   <span class="token string">"fmt"</span>
   <span class="token string">"math"</span>
<span class="token punctuation">)</span>
func <span class="token function">calculateVolumeOfCone</span><span class="token punctuation">(</span>h<span class="token punctuation">,</span> r float64<span class="token punctuation">)</span> float64 <span class="token punctuation">{</span>
   
   <span class="token comment">// declaring variable ?volume? for storing the volume of the cone</span>
   <span class="token keyword">var</span> volume float64 <span class="token operator">=</span> <span class="token number">0</span>
   
   <span class="token comment">// calculating the volume of the cone using its formula</span>
   volume <span class="token operator">=</span> <span class="token punctuation">(</span><span class="token number">1.0</span> <span class="token operator">/</span> <span class="token number">3.0</span><span class="token punctuation">)</span> <span class="token operator">*</span> <span class="token punctuation">(</span><span class="token number">22.0</span> <span class="token operator">/</span> <span class="token number">7.0</span><span class="token punctuation">)</span> <span class="token operator">*</span> r <span class="token operator">*</span> r <span class="token operator">*</span> h
   <span class="token keyword">return</span> volume
<span class="token punctuation">}</span>
func <span class="token function">calculateAreaOfCone</span><span class="token punctuation">(</span>h<span class="token punctuation">,</span> r float64<span class="token punctuation">)</span> float64 <span class="token punctuation">{</span>
   <span class="token comment">// declaring variable ?area? for storing the area of the cone</span>
   <span class="token keyword">var</span> area float64 <span class="token operator">=</span> <span class="token number">0</span>
   
   <span class="token comment">// calculating the value of length 'l'</span>
   l <span class="token operator">:</span><span class="token operator">=</span> <span class="token class-name"><span class="token namespace">math<span class="token punctuation">.</span></span>Sqrt</span><span class="token punctuation">(</span><span class="token punctuation">(</span>r <span class="token operator">*</span> r<span class="token punctuation">)</span> <span class="token operator">+</span> <span class="token punctuation">(</span>h <span class="token operator">*</span> h<span class="token punctuation">)</span><span class="token punctuation">)</span>
   
   <span class="token comment">// calculating the area of the cone using its formula</span>
   area <span class="token operator">=</span> <span class="token punctuation">(</span><span class="token number">22.0</span> <span class="token operator">/</span> <span class="token number">7.0</span><span class="token punctuation">)</span> <span class="token operator">*</span> r <span class="token operator">*</span> <span class="token punctuation">(</span>r <span class="token operator">+</span> l<span class="token punctuation">)</span>
   <span class="token keyword">return</span> area
<span class="token punctuation">}</span>
func <span class="token function">main</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
   
   <span class="token comment">// declaring variable ?height? for storing the height of the cone</span>
   <span class="token keyword">var</span> h float64 <span class="token operator">=</span> <span class="token number">7</span>
   
   <span class="token comment">// declaring variable ?radius? for storing the radius of the cone</span>
   <span class="token keyword">var</span> r float64 <span class="token operator">=</span> <span class="token number">5</span>
   
   <span class="token comment">// declaring variables ?area? and ?volume? for storing the area and volume of the cone</span>
   <span class="token keyword">var</span> area<span class="token punctuation">,</span> volume float64
   <span class="token class-name"><span class="token namespace">fmt<span class="token punctuation">.</span></span>Println</span><span class="token punctuation">(</span><span class="token string">"Program to calculate the volume and area of the Cone \n"</span><span class="token punctuation">)</span>
   
   <span class="token comment">// calling function calculateVolumeOfCone() for</span>
   <span class="token comment">// calculating the volume of the cone</span>
   volume <span class="token operator">=</span> <span class="token function">calculateVolumeOfCone</span><span class="token punctuation">(</span>h<span class="token punctuation">,</span> r<span class="token punctuation">)</span>
   
   <span class="token comment">// calling function calculateAreaOfCone() for calculating</span>
   <span class="token comment">// the area of the cone</span>
   area <span class="token operator">=</span> <span class="token function">calculateAreaOfCone</span><span class="token punctuation">(</span>h<span class="token punctuation">,</span> r<span class="token punctuation">)</span>
   
   <span class="token comment">// printing the results</span>
   <span class="token class-name"><span class="token namespace">fmt<span class="token punctuation">.</span></span>Println</span><span class="token punctuation">(</span><span class="token string">"Height of the cone : "</span><span class="token punctuation">,</span> h<span class="token punctuation">)</span>
   <span class="token class-name"><span class="token namespace">fmt<span class="token punctuation">.</span></span>Println</span><span class="token punctuation">(</span><span class="token string">"Radius of the cone : "</span><span class="token punctuation">,</span> r<span class="token punctuation">)</span>
   <span class="token class-name"><span class="token namespace">fmt<span class="token punctuation">.</span></span>Println</span><span class="token punctuation">(</span><span class="token string">"Therefore, Volume of cone : "</span><span class="token punctuation">,</span> volume<span class="token punctuation">)</span>
   <span class="token class-name"><span class="token namespace">fmt<span class="token punctuation">.</span></span>Println</span><span class="token punctuation">(</span><span class="token string">"Area of cone : "</span><span class="token punctuation">,</span> area<span class="token punctuation">)</span>
<span class="token punctuation">}</span>
</div><div class="output-wrapper"><div class="console-close"></div><div class="code-output"></div></div>

Output

Program to calculate the volume and area of the Cone 

Height of the cone :  7
Radius of the cone :  5
Therefore, Volume of cone :  183.33333333333331
Area of cone :  213.75082562495555

Description of code

• var h float64 = 7, var r float64 = 5 ? In this line, we are declaring the variables for height ?h? and radius ?r?.

• calculateVolumeOfCone(h, r float64) float64 ? This is the function where we are calculating the volume of the cone. The function has the variable ?h? and ?r? of data type float64 as the parameter and also has a return type of float64.

• volume = (1.0 / 3.0) * (22.0 / 7.0) * r * r * h ? If we desire the output to be of data type float, we explicitly need to convert the values, that is the reason we are using values 22.0 and 7.0 instead of 22 and 7. Using the above formula, we can calculate the volume of the cone.

• return volume ? for returning the volume of the cone.

• volume = calculateVolumeOfCone(h, r) ? We are calling the function calculateVolumeOfCone() and storing the calculated value in the ?volume? variable in the main method.

• calculateAreaOfCone(h, r float64) float64 ? This is the function where we are calculating the area of the cone. The function has the variable ?h? and ?r? of data type float64 as the parameter and also has a return type of float64.

• l := math.Sqrt((r * r) + (h * h)) ? We will need the value of length ?l? for calculating the area of the cone.

• area = (22.0 / 7.0) * r * (r + l) ? Using this formula, we calculate the area of the cone.

• return area ? for returning the area of the cone

• area = calculateAreaOfCone(h, r) ? We are calling the function calculateAreaOfCone() and storing the calculated value in the ?area? variable.

Conclusion

This is all about calculating the volume and area of a cone using Go programming. We have also maintained code modularity by using separate functions for calculating the area and volume which also increases the code reusability. You can explore more about Golang programming using these tutorials.