PLEASE help me, i have no clue?

Question

In rectangle ABCD, diagonal AC measures 11 cm and side AB measures 7cm. Find to the nearest degree the measure of angle CAB.

please show me how to do this

Answer 1

Actually all the information given are in the right triangle ABC and ask you the size of angle A. If you know trig, this would be easy, since:
cos A = AB/AC = 7/11
thus A = arc cos (7/11) ≈ 50 (degree)