we got 3 rectangles and 2 triangles
we can unfold it and manuvore it to be 2 trianges and 1 long rectangle
for the triangles, we need to use the pythagorean theorem to find the height or other side
one leg is 15
the hyptohus is 17
so
remember if the legs are a and b and hypohtuse is c then
a²+b²=c²
so
15²+b²=17²
225+b²=289
b²=64
b=8
so the height is 8
and since there are 2 triangles, the area of those will be 2*1/2*15*8=15*8=120
rectangle
area=lenght times width
if we unfold it then we can get a long rectangle with length 15+17+8 and width 20
the long rectangle is (15+17+8)(20)=(40)(20)=800 square inches
toal is 120+800=920 square inches
