17)

Triangle are similar.

Observe the triangles,

Since,

The equations are 

Find

The value of

18)

Triangle are similar.

Observe the triangles,

Since,

The equations are 

Find

The value of

19)

Observe the circle.

Angle measures

Point is the center of the circle.

Find arc measures.

The measure of an arc is equal to the central angle.

Since is the center of the circle, is the central angle for the arc AB. \ \ The arc is angle

20)

Observe the circle.

Angle measures

Point is the center of the circle.

Find arc measures.

The measure of an arc is equal to the central angle.

Here is the center of the circle, is the central angle for the arc .

Since, Point D is NOT LOCATED.

It is not possible to measures arc .

21)

Observe the triangles,

Consider the center of the point is c.

Triangle are congruent.

Observe the triangles,

Since,

Find

The value of