Lesson 60

Geometric Solids

Prisms & Cylinders

Geometric Solids

• right triangular prism

• right circular cylinder

• regular square pyramid

• right circular cone

• sphere

Definitions

• prism: two faces are identical & parallel, other faces are parallelograms

• lateral edges: where the lateral faces (parallelograms) intersect

• altitude: perpendicular segment joining the planes of the bases

• height: length of the altitude

Cylinders

• lateral surface: curved surface between the bases

• axis: segment joining the centers of the bases

• altitude: perpendicular segment joining the planes of the bases

• height: length of the altitude

Volume of Prisms and Cylinders

• equal to the area of a base times its height

BhV

Example 60.1

• The area of a base of a right pentagonal prism is 28 cm2 and the length of a lateral edge is 10 cm. Find the volume.

Lateral Surface Area of Right Prisms & Right Cylinders

• equal to the perimeter of a base times the height

• LSA: the area of all surfaces other than the bases

Example 60.2

• Find the lateral surface area of this right prism whose bases are regular pentagons. Dimensions are in meters.

15

8

Example 60.3

• The area of a base of a right pentagonal prism is 34 in2 and the length of a lateral edge is 12 in. Find the volume of the right pentagonal prism.

Example 60.4

• Find the lateral surface area of this right prism whose bases are regular pentagons. Dimensions are in feet.

16

12

Homework

• P.S. 60

• 2-30 even