SOH CAH TOA is a useful mnemonic.
9) Sin(Z) = Opposite/Hypotenuse = 24/40 = 3/5
Cos(Z) = Adjacent/Hypotenuse = 32/40 = 4/5
Tan(Z) = Opposite/Adjacent = 24/32 = 3/4
10) Same as above
sin(K) = k/j
cos(K) = h/j
tan(K) = k/h
11) The area of an equilateral triangle is (√3)/4 times the square of the side length. You have 4 such triangles, so the total area is ...
area = (√3)×(18 m)²
area = 324√3 m²
area ≈ 561.18 m²
12) cos(A) = √(1 -sin(A)²)
cos(A) = √(1 - (25/169)) = √(144/169)
cos(A) = 12/13