Geometry

Chapter 9

9.3: Surface Area and Volume of Pyramids

Parts of a Pyramid

• Base: polygon• Lateral faces: triangles• Vertex: where all ‘s meet• Base edge: where and base meet• Lateral edge: intersection of 2 • Altitude: perp segment from base to vertex• Height: length of altitude

• Regular Pyramid: base is regular polygon• Slant height: altitude of lateral face

7.3 Surface Area and Volume of Pyramids

Surface Area of a Regular Pyramid:

S = 12 lp + B .

B=base area

p= perimeter

l= slant height

Volume of a Pyramid :

13 BhV = .

H=height

B=base area

Key Skills7.3 Surface Area and Volume of Pyramids

Find the surface area of a regular pyramid.

S =12

lp + B

Key Skills7.3 Surface Area and Volume of Pyramids

Find the volume of a regular pyramid.

V =13

Bh

TOC

If the surface area of the pyramid is 180 cm, find x.

• The surface area of a square pyramid

is 864 m, if the slant height is 15m and the

height is 12 m, what is the length of each

side of the base?