1. Surface Area of Pyramids, Cones and Spheres
Math 8
Measurement Unit

2. How can I calculate the surface area?
SA of Pyramids
If we were to look at a net of a square pyramid, it would look like the diagram below:
How can I calculate the surface area?

3. What about a triangular pyramid?
How would I calculate the SA of this figure?

4. Formulas to Calculate SA of Pyramids
Formula to calculate the area of a triangular face:
A = b X h ÷ 2
To calculate a triangular base of a pyramid:
To calculate a square base of a pyramid:
A = base X base

5. Let’s try one:
Calculate the SA of the following pyramid (include the base):

6. Solution

7. How can I calculate the surface area?
SA of Cones
If we were to look at a net of a cone, it would look like the diagram below:
How can I calculate the surface area?

8. Formulas to Calculate SA of Cones
Formula to calculate the area of the cone base:
A = ∏●r2
To calculate the lateral face of a cone:
A = ∏●r●l (slant height)

9. Let’s try one:
Calculate the SA of the following cone (include the base):

10. Solution

11. SA of Spheres To calculate the SA of a sphere, the formula is:
A = 4●∏●r2

12. Let’s try one:
Calculate the SA of the following sphere:

13. Solution