Download presentation

Presentation is loading. Please wait.

Published byThomasine Chandler Modified over 5 years ago

1
Surface Area of Pyramids and Cones

2
Vocabulary Regular pyramid- a pyramid whose base is a regular polygon, and the faces are congruent isosceles triangles. Slant height of a pyramid- the distance from the vertex to the midpoint of an edge of the base. Slant height of a cone- the distance from the vertex to a point on the edge of the base.

3
The diagram shows a square pyramid. The blue dashed line labeled l is the slant height of the pyramid, the distance from the vertex to the midpoint of an edge of the base. The base of a regular pyramid is a regular polygon, and the faces are congruent isosceles triangles.

5
Additional Example 1A: Finding the Surface Area of a Pyramid Find the surface area of the pyramid. S = 81 + 180 S = 261 m 2 S = B + Pl 1212 S = (9 9) + (36)(10) 1212 Use the formula. S = lw + Pl 1212 B = lw Substitute. P = 4(9) = 36 Add. The surface area is 261 square meters.

6
Additional Example 1B: Finding the Surface Area of a Pyramid Find the surface area of the pyramid. S = 62.28 + 108 S = 170.28 S = B + Pl 1212 Use the formula. B= ½bh. S = bh + Pl 1212 1212 S = (12)(10.38) + (36)(6) 1212 1212 The surface area is 170.28 m 2.

7
Check It Out: Example 1A Find the surface area of each pyramid.

8
Check It Out: Example 1B Find the surface area of the pyramid

9
The diagram shows a cone and its net. The blue dashed line is the slant height of the cone, the distance from the vertex to a point on the edge of the base.

11
Additional Example 2: Finding the Surface Area of a Cone Find the surface area of the cone. Use 3.14 for . Use the formula. S ≈ 122.46 S = r 2 + rl S ≈ (3.14)(3 2 ) + (3.14)(3)(10) S ≈ 28.26 + 94.2 The surface area is about 122.46 square centimeters. Substitute. Multiply. Add.

12
Check It Out: Example 2A Find the surface area of the cone. Use 3.14 for .

13
Check It Out: Example 2B The dimensions of the cone from Exercise 2a quadrupled. Find the surface area of the cone. Use 3.14 for .

Similar presentations

© 2021 SlidePlayer.com Inc.

All rights reserved.

To make this website work, we log user data and share it with processors. To use this website, you must agree to our Privacy Policy, including cookie policy.

Ads by Google