Finding the area of a shape is one of the first steps to becoming a geometry whiz. Once you master two-dimensional shapes like quadrilaterals, triangles and circles, you’re ready to find the area of more complex three-dimensional shapes that you see every single day – probably without even realizing it. Knowing how to find the area of these three-dimensional shapes can come in handy in real-world situations. In fact, with the formula I’m going to give you, you can calculate the area of a sphere you’re standing on right now!
The formula to calculate the area of a sphere is 4πr². Just for a general reminder, π is an irrational number that continues into eternity and is usually represented by the approximate value of 3.141. R stands for radius, which is the distance from the center of a sphere to its outermost point. This simple formula can be explained in more detail if you want some equations homework help. The area of a shape is essentially the amount of space its surface takes up. In case you hadn’t figured it out yet, the sphere you’re standing on right now is none other than the planet Earth. Don’t worry about driving from the Earth’s center to the outermost point – scientists have determined that the Earth’s radius is about 3,959 miles. Multiply the radius by itself and you’ll end up with 15,673,681 miles². Multiply that value by π, which comes out to approximately 49,240,279.5 miles². Finally, multiply that value one more time by 4, and you’ll find that the area of the Earth is approximately 196,961,118 miles².
It’s really that simple! Once you know the radius of any sphere, you can plug the value straight into the formula and find the area of everything from your brother’s baseball to the pit of the avocado you ate for breakfast. You’ll become a master in no time and can then move to calculating the volume of a sphere.