Finding value of r with arc length formula.

[polar pecan]

I tried to solve number 9 like this
28 = (50/360) * 2 * pi * r
=> (28 * 360)/(50 * 2 * pi * )= r
= > r = 32.08563653 cm.. Now that should've been the answer but apparently not, it's 6.06 cm how!!!

[manic swallow]

The problem is that you have only calculated the arc of the smaller circle in the left side of your equation. You are missing some parts of the perimeter @polar pecan

[orchid schooner]

This is easy.

[manic swallow]

I know that it is. But everyone had to learn it once.

[chilly lark]

(50/360)×2pi×r+(50/360)×2pi×2r+2×2r = 28
solve for r

[polar pecan]

I'm not trying to find the perimeter, only the value of r