1) this is total area of two triangle area of a triangle=1/2*b*h A=1/2*9*4 A=18 inches^2 multiply by 2 because there are two triangle with same measure 2A=2*18=36 inches^2
3) this is a area of rectangle and a triangle and then subtract A2=9.3x7.8= 72.54 area of triangle A1=1/2*7.8 *3.3=12.87 A2-A1=59.69 mm^2