Finding the volume of a sphere (diameter given)

by Sabrina
(USA)

Question

Find the volume of the sphere where its diameter is 15 inches. Take π=3.14.

Answer

Now, let's take a look at the sphere below:
Alright, since we are finding the volume of a sphere, we will be using the following volume formula:
where π is a number that is approximately equals to 3.14 (or use the number given to you) and r is the radius of the sphere.

Note that, to use the formula, we need the value of the radius. Since the radius is half of the diameter, we can find the value of the radius by dividing 15 with 2. This is shown below:With the radius, r=7.5 inches, we can calculate for the volume of the sphere as shown below:Now, it is important to include the unit. Since the radius is in inches. The volume will be in cubic inches. Therefore: