An inscribed angle is an angle formed by two radii that share an endpoint a) true b)false

Check the picture below.

notice, as from the left, we grab those two angles and slap them together on the right, they form a wide angle A, and a smaller inscribed angle B.

now, the blue and red segments that came together, are both making up the inscribed angle B, and also sharing the side or endpoint, in the middle of angle A.