# Geometry Unit 9 Lesson 3 (12/16)

Monday
12/16/2013
Notes:
12.3 Surface Areas of Pyramids and Cones
12.5 Volumes of Pyramids and Cones
G.14a, G.13

p. 843 – 844 – #7, 9, 13, 19, 25, 28, 32

p. 860 – 861 – #11, 12, 13, 16, 18, 24, 29, 37

Unit 9 Lesson 3

Clean sheet: Titled “Lesson 2: Prisms and Cylinders”

• Naming Pyramids “Base + Pyramid”

• Volume of a Prism: Bh where B is the area of the base.

• Volume of a Pyramid: 1/3 a Prism
• Volume of a Cylinder: Bh where B is the area of the base (pi r^2)

• Volume of a Cone: 1/3 a Cylinder

Examples 1-4: Find the Volume.

• Lateral Area: Area of the faces of a polyhedron not including bases.

• l is Slant Height
• Surface Area of a Pyramid: 1/2 lp +B

• Surface Area of a Cone: 1/2 lp + B

• But the perimeter of a circle is the circumference or 2pi r. and the B=pi r^2

• So the SA of a Cylinder: l(pi r)+(pi r^2)

Examples 5-8: Find the Lateral and Total Surface Area.

GUIDED PRACTICE

Whiteboards

Practice with solving the V and SA of all Solids so far.