Question

Please help if you know how to do this type of math! :)

Answer 1

It's just a tiny bit sloppy. The 10.2 cm should be designated with a right angle too. I'll answer it that way.

Area = (L1 + L2)*h/2
L1 = 10.2
L2 = 12.2
h = 12.6 
all givens are in cm.

Area = (10.2 + 12.2)*12.6/2
Area = 22.4 * 6.3
Area = 78.12 cm^2