If r is the radius of a circle and d is its diameter, which of the following is an equivalent formula for the circumference C=2πr? A. C=2πd B. C=πD C. C=πr2 D. C=πdr

Question

asked Dec 15, 2017 32.8k views

2 Answers

Cinnamon · Answer 1 · 2017-12-20T02:07:32+0000

Answer:

Option B is correct

C=πD

Explanation:

As per the statement:

If r is the radius of a circle and D is its diameter.

Given the circumference of the circle:

$C = 2 \pi r$ .....[1]

where,

r is the radius of the circle.

We know that:

diameter(D) = 2r

Substitute in [1] we have;

$C = \pi (2r) = \pi D$

Therefore, the equivalent formula for the circumference C=2πr is, C=πD