1. If I have two coplanar lines, I must have a plane.

A. unfounded

B. Definition of a point

C. Definition of a plane

D. Given

E. Definition of a line

F. Definition of radius

2. There are two adjacent angles whose outside edges form a straight line. The measure of the first angle is 100 degrees, so the measure of the other must be 80 degrees.

A. Given B. Definition of supplementary angles C. Definition of an octagon D. unfounded E. Definition of radius F. 1267200 inches

3. I have drawn a polygon with eight sides, so it must be an octagon.

A. Definition of supplementary angles B. unfounded C. Definition of radius D. 1267200 inches E. Definition of an octagon F. Given

4. A square has two diagonals.

A. Given B. unfounded C. Definition of an octagon D. The number of diagonals is (n-3)n/2, where n is the number of sides, which is 4 for a square. E. 1267200 inches F. Definition of supplementary angles

5. If the diameter of the circle is 12, the radius must be 6.

A. Definition of radius B. 1267200 inches C. Definition of an octagon D. Definition of supplementary angles E. unfounded F. Given

G A M E F