If the lengths of the bases of an isosceles trapezoid inscribed in a circle are 10 cm and 22 cm, and if one of the legs is 10 cm, then the length of a diagonal, in cm, is?
a) 6√10
b) 8√5
c) 6√3
d) 10√3
e) 12√2
We can find the height of this trapezoid as follows.....
h = sqrt [ 10^2 - 6^2] = sqrt [100 - 36 ] = sqrt [ 64] = 8
And the length of the diagonal will be the hypotenuse of a right triangle with legs of 8 and 16
So....the diagonal is
sqrt [ 8^2 + 16^2] = sqrt [ 8^2 ( 1 + 2^2) ] = 8 sqrt (5) units