Question

Find the surface area of the composite solid.

A.

680 in.2

B.

800 in.2

C.

920 in.2

D.

1,040 in.2

Answer 1

we know that

surface area=2*area of the base+perimeter of base*height

area of the base=b*h/2

b=8 ft

h=15 ft

so

area of triangle=8*15/2-------> 60 ft²

perimeter of base=a+b+c

a=15 ft

b=8 ft

c=?

applying the Pythagoras theorem

c²=a²+b²------> c²=15²+8²------> c²=225+64------> 289

c=√289------> c=17 ft

perimeter=15+8+17=40 ft

height of the prism=20 ft

surface area=2*60+40*20------> 920 ft²

the answer is the option

B. 920 ft 2