turkey-yks 2019 Q36

turkey-yks · Other · yks-tyt Not Maths
The circumference of a circle with radius r is $\text{C} = 2\pi r$, and the area of a circle with radius r is calculated with the formula $A = \pi r^{2}$.
In the figure; a rope that completely wraps around a semicircle with radius R once is unwound and divided into three equal parts. One of these equal parts completely wraps around a semicircle with radius r once.
Accordingly, what is the ratio of the area of the semicircle with radius $R$ to the area of the semicircle with radius $\mathbf{r}$?
A) 3
B) 4
C) 6
D) 8
E) 9
The circumference of a circle with radius r is $\text{C} = 2\pi r$, and the area of a circle with radius r is calculated with the formula $A = \pi r^{2}$.

In the figure; a rope that completely wraps around a semicircle with radius R once is unwound and divided into three equal parts. One of these equal parts completely wraps around a semicircle with radius r once.

Accordingly, what is the ratio of the area of the semicircle with radius $R$ to the area of the semicircle with radius $\mathbf{r}$?

A) 3

B) 4

C) 6

D) 8

E) 9