Lesson 11-3
Surface Areas of Pyramids and Cones
Find the surface area of a pyramid.
Find the surface area of a cone.
Vocabulary
pyramid ________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________
vertex of a pyramid _______________________________________________________________
regular pyramid__________________________________________________________________
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slant height of a regular pyramid ___________________________________________________
________________________________________________________________________________
altitude of a pyramid______________________________________________________________
________________________________________________________________________________
Lateral and Surface Areas of Pyramids
The lateral area of a regular pyramid is half the product
of the perimeter of the base and the slant height.
The surface area of a regular pyramid is the sum of the
lateral area and the area of the base.
cone ____________________________________________________________________________
________________________________________________________________________________
vertex of a cone __________________________________________________________________
axis of a cone ____________________________________________________________________
________________________________________________________________________________
right cone _______________________________________________________________________
oblique cone _____________________________________________________________________
slant height of a right cone _________________________________________________________
altitude of a cone _________________________________________________________________
Pearson Prentice Hall Geometry
Lesson 11-3
Page 1 of 2
Lateral and Surface Areas of Cones
The lateral area of a right cone is half the product of the
circumference of the base and the slant height
The surface area of a right cone is the sum of the lateral
area and the area of the base
Examples
Finding Surface Area of a Pyramid
Find the surface area of a square pyramid with base edges 7.5 ft and slant height 12 ft.
Finding Lateral Area of a Pyramid
Find the lateral area of the hexagonal pyramid below. Round answer to the nearest whole number.
Finding Surface Area of a Cone
Find the surface area of the cone in terms of π.
Real- World Connection
Leandre uses paper cones to cover her plants in the early spring. The diameter of each cone is 1 ft,
and its height is 1.5 ft. How much paper is in the cone? Round your answer to the nearest tenth.
HW (11-3): pp.620-623 #1, 5, 9, 12, 14, 17-19, 23, 25-27, 30, 39, 43-49
Checkpoint Quiz 1 page 623 #1-10
Pearson Prentice Hall Geometry
Lesson 11-3
Page 2 of 2