Warm up!Find the surface area of the backpack to

the nearest inch:

bhAThe base is 12 in, but what is the height? (Hint: what is the radius of the circle?)

1112A132A

The back has the same area:

264backfrontA

bhA

114A

44AThe left side has the same area:

88rightleftA

bhA

124A

48A

2

21 rA

2621A

55.56AThe back has the same area:

1.113backfrontA

rhA 221

rhA 46A

4.75A

4.75A

264backfrontA88rightleftA48A

1.113backfrontA

2in589A

Spheres

GeometryUnit 6, Day 6Mr. Zampetti

What is a Sphere?

Definition:A 3-dimensional circle.

Examples:

Formulas

Surface Area Volume

24 rSA 3

34 rV

Example #1

Calculate the volume of:

15”V = 4/3 r3

V = 4/3(15)3

V 14130in3

Example #2

Calculate the volume of:

V = 4/3 r3

V = 4/3(3.9)3

V 248.349in3

Example #3

Calculate the surface area of:

S = 4r2

S =4(6.1)2

S 467.3576 in2

Homework

Work Packet:Spheres