Hello. I need help a few math probs.. ?

Question

Here is the picture for the questions:

http://img144.imageshack.us/img144/5354/cindimathte8.png

21. If AC = 4x + 5 and DC = 3x + 8, find AC.

22. If M(angle sign)BCE= 45 and M(angle sign)ECD= 65, find M(angle sign)BCD

23. If M(angle sign)FCA =40, find M(angle sign)FCD

Thank YOU!

Answer 1

Use the pythagorean theorem

a(squared)+b(squared)=c(squared)

Answer 2

According to the picture AC = DC

4x-3x = 8-5

x = 3

AC = 17

(angle)BCD = 110(degrees)

180 - 40 = 140(degrees) = (angle)FCA

No need to use Pythagorean theorem for any of it