The sum of two negative numbers will always be?

Match the term on the left with its image or description on the right. match term definition diameter a) circle a and a line segment connecting points b and c which are on the circle. circumference b) circle a and a line segment connecting points b and c which are on the circle. radius c) a piece of the circumference of a circle secant d) two circles that share the same center. concentric circles e) the distance around a circle arc f) a segment between two points on a circle that passes through its center

What is the measure of ac? 5 units 13 units 26 units 39 units

Idon’t understand this.. will someone ? will mark brainliest along with 20 points.