To solve for EP you have to first identify the radius (half of the diameter)
10/2 = 5
Then plug in the length of the hypotenuse and the radius in the pythagorean theorem.
a^2 + b^2 = c^2
5^2 + x^2 = 12^2
Then subtract 5^2 on both sides
x^2 = 144 - 25
x^2 = 119
Then find the square root of 119
so x = 10.908 and round to the nearest hundredth.
x=10.91