3. Find the diameter of a circle with a circumference of 50 mm. Round your answer to the nearest tenth.

16.0 mm

26.4 mm

8.4 mm

33.5 mm

1) Equation that you need is:

C = 2πr

The diagram shows that the radius is 3.5, so plug it in the equation and solve for C

C = 2 (3.14) (3.5)

C = 21.98

Rounded to tenth: 22.0

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2) The equation you need to know here is:

A = πr²

The diagram shows diameter is 12, so radius is 6. Plus in the info, we have and solve for A

A = 3.14 (6) ²

A = 113.04

rounded to tenths: 113.0

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3) Find the diameter of a circle with a circumference of 50mm.

C = 2πr

50 = 2 (3.14) r

50 = 6.28r

r = 50 / 6.28

r = 7.96

You were asked to find the diameter, so double that, then round it to tenths:

d = 2r

d = 2 (7.96)

d = 15.92

Rounded to 15.9mm