Unit 4B

Area of a circle

100

What is the formula to find area of a circle? 

πr²

200

The radius of a circle is 8 ft. What is the area?

(Use π ≈ 3.14)

200.96

300

A circle has a radius of 5 cm. What is the area?
(Use π ≈ 3.14)

200.96

400

A circle has a diameter of 10 cm. What is the area?

78.5cm

500

Sally is solving to find the area of a circle, the following are the steps she took. What step(s) did she do wrong and what are the correct steps? A circle has a diameter of 12, find the area 

Step 1: a=π + r²

Step 2:a =3.14 x 12²

Step 3: a = 3.14 x 144

Step 4: a = 452.16 

Answers will vary but she:
1. Incorrect formula, used + instead of x 

2. Did not divide the diameter by 2

3. Should have multiplied 3.14 x 36

4. correct answer is 113.04 

Circumference of a circle

100

What is the formula to find the circumference of a circle if I am given the diameter? 

c=π x d

200

Find the circumference of a circle with diameter 12 m.

(Use π ≈ 3.14)

37.68

300

The radius of a circle is 9 in. What is the circumference?

56.52

400

A circular running track has a radius of 25 m. What is the circumference?

157

500

The circumference of a circle is 31.4 cm. What is the diameter?

10

Rectangular Prisms Surface Area

100

Find the surface area.
l = 4 cm
w = 3 cm
h = 2 cm

SA = 2(lw + lh + wh)
SA = 2(12 + 8 + 6)
SA = 52 cm²

200

Find the surface area.
l = 6 m
w = 5 m
h = 2 m

104m²

300

Find the surface area.
l = 8 in
w = 3 in
h = 4 in

SA = 2(24 + 32 + 12)
SA = 136 in²

400

Find the surface area.
l = 10 ft
w = 7 ft
h = 3 ft

SA = 2(70 + 30 + 21)
SA = 242 ft²

500

A rectangular prism has:
l = 15 cm
w = 10 cm
h = 6 cm

SA = 2(150 + 90 + 60)
SA = 600 cm²

Rectangular Prisms Volume

100

What is the formula for volume of a rectangular prism? 

Volume = length x width x height 

200

Find the volume.
Length = 5 cm
Width = 4 cm
Height = 3 cm

V = lwh
V = 5×4×3 = 60 cm³

300

Find the volume.
Length = 8 m
Width = 6 m
Height = 2 m

V = 8×6×2 = 96 m³

400

A box measures 10 in by 4 in by 6 in. What is the volume?

V = 240 in³

500

A rectangular prism has:
l = 12 cm
w = 5 cm
h = 7 cm

V = 12×5×7 = 420 cm³

Cylinders

100

What is the formula to find volume of a cylinder? 

v=πr²h

200

Find the volume of a cylinder.
r = 3 cm
h = 5 cm

V = πr²h
V = 3.14(9)(5) = 141.3 cm³

300

Find the volume of a cylinder.
r = 4 m
h = 6 m

V = 3.14(16)(6)
V = 301.44 m³

400

Find the surface area of a cylinder.
r = 3 cm
h = 7 cm

SA = 188.4 cm²

500

Find the surface area of a cylinder.
d = 6 ft
h = 10 ft

244.92ft²