1 pie with diameter of a to b then radius of top to bottom half of c to o

the chord is angle cob right. the questions are

a. which chord is not a diameter
b. name a central angle that is a right angle
c. name a inscribed angle

I cannot visualize your picture from the description you provided. I have no idea what you man by "radius of top to bottom half of c to o". Punctuating and capitalizing new sentences would help