4. A rectangle ABCD, which measures 9ft by 12ft, is folded once perpendicular to diagonal AC so that the opposite vertices A and C coincide. Find the length of the fold.

5. Line AC = 3, Line BC = 4, Line EF = 2

DEFG is a rectangle. ABC is a right triangle. DE is perpendicular to AB. Find the area of DEFG

Thanks for helping!