Find the circumference and length of the darkened part of the arc. Leave answer in terms of pi

Circumference = 56.52

Length of the darkened part of the arc = 3.6π

Solution:

Radius of the circle = 9

Circumference of the circle = 2πr

                                              = 2 × π × 9

Circumference of the circle =  18π

Equal number of parts = 5

Total degree of circle = 360°

Degree of the darkened part =

                = 3.6π

Circumference = 18π

Length of the darkened part of the arc = 3.6π

it has to have an angle of 90 degrees

it's possible to build a triangle with side lengths of 3, 3, and 9.- true ( b.)