During this week of math 10 we started working with spheres. A sphere is a round solid figure, or its surface, with every point on its surface equidistant from its centre. A sphere is 2 hemispheres. The diameter of the sphere which is a straight line passing from side to side through the center of a body or figure, especially a circle or sphere. The radius of a sphere is the diameter divided by two. Radius(r) is half of the diameter(d). In this blog post I’m going to teach you how to get the SA and V of a sphere and then convert it into SA and V of a hemisphere (half a sphere). To find the SA of a sphere the formula we use is 4 x pie x r squared. Let’s say we were told that the d of the circle is 18cm.

Then to find the V of a sphere we use the formula 4/3 x pie x r cubed. Now if we know the r is equal to 9cm then all we need to do is convert the 4/3 into a decimal and follow through with the given formula.

Now to convert the V into a hemisphere you simple divide by tow because the sphere is just two hemispheres. So if our V of the sphere was equal to 3053.62 cm cubed the V for a hemisphere would equal 1526.81cm cubed.

Now to get the SA of the hemisphere form the spheres SA, it isn as easy has just divide by 2 because when you cut the sphere in half you have an extra side which is the flat top. This hemisphere is a dome shape. You use the formula 3 x pie x r squared. So with the formula you can now find the SA of the hemisphere.