Suppose small lights are going to be hung from one corner of a room to the opposite

Hello!

1) A and D

The radius is the distance from the center of a circle to any part of the edge. Both A and D have a radius of three, regardless of what direction they go.

2)  5"

In circle C we see that there is a line segment that is 5" that goes from the center to the edge, or the radius.

3) C

The different variables are representing different points on the circles. The circle that contains a line connecting C and L is circle C.

4) BN

Circle B contains a radius that is the distance from B to N, or BN.

5) EF

The diameter is the distance of a  straight line that was pass through the middle of a circle, or its width. The diameter is double the radius. In circle A we see that line EF passes through the center put goes all the way across the circle.

6)IJ

Line IJ isn't even linear, so it could not be the radius. Both AG and BH are straight lines that represent the radius.

7) 6"

The diameter is always twice the radius. In circle A the radius is 3, so the diameter is 6.

8) A and D

Just as we said in the first answer, A and D both have a radius that measures 3 inches.

I hope this helps!