Hello, Cthul

The perimeter of the shape formed by major arc and chord is 30 m.

Find the radius

Code:* * * * * * * * * * O * * ♥ * * r *120* r * * * * * * * A ♥ - - - - - - - ♥ B * * * * *

The circumference of the circle is:

The major arc has length:

Using the Law of Cosines on

. .

Hence: .

The perimeter is: .

. . . . . . . . . . . .

Therefore: .