Section A Section A Checkpoint

Problem 1

Select all the equations that correctly state a relationship between the radius ( $r$ ), diameter ( $d$ ), and circumference ( $C$ ) of a circle.

A

C = \pi r

B

d = \pi r

C

C = 2 d

D

C = \pi d

E

r = \frac12 d

F

C = 2 \pi r

Show Solution

Solution

D, E, F

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Sample Response

D, E, F

Problem 2

A wagon wheel has a radius of 21 inches. What is the circumference of the wheel? Explain or show your reasoning.

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Solution

About 132 inches.

21 \boldcdot 2 = 42

, and

42 \boldcdot 3.14 \approx 132

.

Show Sample Response

Sample Response

About 132 inches.

21 \boldcdot 2 = 42

, and

42 \boldcdot 3.14 \approx 132

.