Question

A circle has its center at the origin, and (5, -12) is a point on the circle. How long is the radius of the circle?

5
12
13

Answer 1

Hello here is a solution :
the radius of the circle is OA A(5;-12) and O (0;0)
OA= square root ((5-0)² + (-12-0)²)
= square root (25+144)
= square root(169)
OA = 13