Click to add text Surface Area of Pyramids, Cones and Spheres Math 8 Measurement Unit

SA of Pyramids If we were to look at a net of a square pyramid, it would look like the diagram below: 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?

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

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: A = b X h ÷ 2 A = b X h ÷ 2 To calculate a square base of a pyramid: A = base X base A = base X base

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

Solution

SA of Cones If we were to look at a net of a cone, it would look like the diagram below: 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?

Formulas to Calculate SA of Cones Formula to calculate the area of the cone base: A = ∏●r 2 To calculate the lateral face of a cone: A = ∏●r●l (slant height) A = ∏●r●l (slant height)

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

Solution

SA of Spheres To calculate the SA of a sphere, the formula is: To calculate the SA of a sphere, the formula is: A = 4● ∏●r 2

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

Solution