Answer:
OA = 13
Explanation:
Use the Pythagorean theorem: a²+b²=c²
a² = OC, the first base, or the radius of the circle, we use the variable x to denote this
b² = 12, this is the other base
x²+12² = (x+8)²
x²+144 = x²+16x+64
-x² -x²
144 = 16x+64
-64 -64
16x = 80
Divide both sides by 16, and you get:
x = 5
Hope this helps!