Spheres Overview
- Author:
- Christine
- Topic:
- Sphere
Sphere Facts
Notice these interesting things:
Volume and Surface Area
Surface Area = 4 × π × r^{2
}
Example: r = 5
Surface Area= 4 × π × r^{2}
= 4 × π × 5^{2}
= 4 × π × 25
= 100 π
≈ 314
Volume = (4/3) × π × r^{3
}
Example: r = 5
Volume= (4/3) × π × r^{3}
= (4/3) × π × 5^{3}
= (4/3) × π × 125
≈ 524
Hemisphere
A hemisphere is an exact half of a sphere.
Other Cool Spheres
- It is perfectly symmetrical
- All points on the surface are the same distance "r" from the center
- It has no edges or vertices (corners)
- It has one surface (not a "face" as it isn't flat)
The Earth: The Planet Earth, our home, is nearly a sphere, except that it is squashed a little at the poles. | It is a spheroid, which means it just misses out on being a sphere because it isn't perfect in one direction (in the Earth's case: North-South) |