### Home > GC > Chapter 12 > Lesson 12.1.2 > Problem 12-18

12-18.

Use the relationships in each diagram below to solve for the given variables.

The secant-tangent angle is half the difference between the major and minor arcs.

The total measure of all the arcs in a circle is 360°.

The area of

is

The area of a circle is

. is the radius of .

The diameter of

is units. is the length of.

Refer to the Math Notes box in Lesson 8.1.4 for help calculating the sum of all of the angles in a polygon.