Hello!
First you have to find BO
BC = 27
AO = CO
CO = 24
BO = 27 + 24
BO = 51
Now we use the Pythagorean Theorem
24^2 + b^2 = 51^2
Square the numbers
576 + b^2 = 2601
Subtract 576 from both sides
b^2 = 2025
Take the square root
b = 45
The answer is A) 45
Hope this helps!
