thursday, february 23 rd

Thursday, February 23rd • Please complete warm up and write down the

Homework • Take out homework (Prism worksheet)

WARM UPThe length of a rectangle is 14 in, the width 6 in, and the height 3 in. 1. Find the Volume

2. Find the surface Area

Joke of the Day What bird is

good at making bread?

A “dough dough”

Homework Answers

Think, Pair, Share

Goal for today

Volume and Surface Area

CYLINDERS

How would you describe:

Net

Of a Cylinder?

Circle Review

A line segment with one endpoint at the center of the

circle and the other endpoint on the circle is a radius (plural: radii). It is half the diameter

CenterRadius

A diameter is a line segment that passes through the center of the circle and has both endpoints on the circle.

The length of the diameter is twice the length of the radius.

CenterRadius

Diameter

The distance around a circle is called the circumference.

CenterRadius

Diameter

Circumference

The formula for the circumference of a circle is C = d, or C = 2r.

Circumference

tttttttttttt

Area

Part 1: Surface Area

1. Using a Net

2. Using a Formula

Nets for Cylinder

Cylinders- the net for a cylinder is made of two congruent circles, and one rectangle.

•The circumference of the circle is the

length of the rectangle

Just WatchArea of Circle:

πr²3 x 5²3 x 2575

2 circles: 75 x 2 = 150

Area of Rectangle: L x WLength= circumference Length= 2πr Length= 2 x 3 x 5 Length = 6 x 5 Length = 30 Area =30 x 10Area = 3002 Areas=600

600 + 150=750

#1 Try Together

Area of 2 Circles:

Area of Rectangle:

#2 You TryArea of 2 Circles:

Area of Rectangle:

#3 You Try

Area of 2 Circles:

Area of Rectangle:

Surface Area with Formulas

SA= 2 πr² + 2πrhSA=__________+__________+__________

SA=__________+__________+__________

SA=__________+__________+__________

SA=_________

#1 Try Together

SA= 2 πr² + 2πrhSA=__________+__________+__________

SA=__________+__________+__________

SA=__________+__________+__________

SA=_________

#2 Try Together

SA= 2 πr² + 2πrhSA=__________+__________+__________

SA=__________+__________+__________

SA=__________+__________+__________

SA=_________

#3 You Try

SA= 2 πr² + 2πrhSA=__________+__________+__________

SA=__________+__________+__________

SA=__________+__________+__________

SA=_________

#4 You Try

Part 2: Volume

To find the volume of a cylinder, you can use the same method as you did for prisms: Multiply the area of the

base by the height.volume of a cylinder = area of base height

The area of the circular base is r2, so the formula is V = Bh = r2h.

Write the formula.

Replace with 3, r with 4, and h with 7.Multiply.V 336

V = r2h

V 3 42 7

The volume is about 336 ft3.

JUST WATCH

10 cm ÷ 2 = 5 cm Find the radius.

Write the formula.

Replace with 3, r with 5, and h with 11.Multiply.V 825

V = r2h

V 3 52 11

The volume is about 825 cm3.

#1 TRY TOGETHER

Multiply.V 540

The volume is about 540 ft3.

6 ft

5 ft

Write the formula.

Replace with 3, r with 6, and h with 5.

V = r2h

V 3 62 5

#2 YOU TRY

Multiply.V 288

8 cm ÷ 2 = 4 cm

The volume is about 288 cm3.

Find the radius.

8 cm

6 cm

Write the formula.

Replace with 3, r with 4, and h with 16.

V = r2h

V 3 42 6

#3 YOU TRY

3-2-1 Summary

3 things you learned

2 things you still need practice on

1 Which way do you like finding surface area: net or formula