Question

Can someone help me with this ?

the answers are :
A : 315
B : 539
C : 469
D : 784

Answer 1

`\large\boxed{S.A.=467\ in^2}`

Explanation:

We have two triangles and three rectangles.

The formula of an area of a triangle:

`A_(triangle)=(bh)/(2)`

b - base

h - height

The formula of an area of a rectangle:

`A_(rectangle)=lw`

l - length

w - width

TRIANGLE:

b = 11 in, h = 7 in

`A_1=((11)(7))/(2)=(77)/(2)=37.5\ in^2`

RECTANGLE 1:

l = 11 in, w = 14 in

`A_2=(11)(14)=154\ in^2`

RECTANGLE 2:

l = 9 in, w = 14 in

`A_3=(9)(14)=126\ in^2`

RECTANGLE 3:

l = 8 in, w = 14 in

`A_4=(8)(14)=112\ in^2`

The Surface Area:

`S.A.=2A_1+A_2+A_3+A_4`

Substitute:

`S.A.=2(37.5)+154+126+112=467\ in^2`