Question 427376

Chord and two radius joining the endpoint of chord and center form an isosceles triangle.

 

the line joining the center and midpoint of chord form a right angle on chord.


by Pythagoras theorem.


( half of chord)^2 + (distance between chord and center)^2 = radius^2

=> (12)^2  + 5^2 = radius^2


=> radius ^2 = 169


so, radius = 13 inches.