Question

(Will mark best answer)

Two circles are shown in the diagram.

Since all circles are similar, a proportion can be set up using the circumference and diameter of each circle. Substitute the values d1 = 1, C1 = π, and d2 = 2r into the proportion.

C1/d1 = C2/d2

Which shows how to correctly solve for C2, the circumference of any circle with radius r?

Answer 1

The first option is correct.

Explanation:

The proportion we have is

`(C_1)/(d_1)=(C_2)/(d_2)`

For the first ratio, we know that C₁ = π and d₁ = 1. This gives us the ratio

π/1.

For the second ratio, we know that d₂ = 2r and we we do not know C₂. This gives us

C₂/2r.

This gives us

`(\pi)/(1)=(C_2)/(2r)`

Cross multiplying, we have

2r(π) = C₂(1)

2πr = C₂

Answer 2

its A i just took the test