Question

The figure below is a net for a triangular prism. Side a = 45 inches, side b = 14 inches, side c = 30 inches, and altitude d = 20 inches. What is the surface area of this figure?
A. 2,370 square inches
B. 1,950 square inches
C. 3,000 square inches
D. 2,790 square inches

Answer 1

Answer:

the answer is A.  2370 sq. in

Step-by-step explanation:

area of the triangles first

A = 1/2 ad

a = (45 in) (20 in)

a = 1/2 (900 sq in)

a = 450 sq in

***remember to multiply 450 * 2 because you have 2 triangles***

Total area of both triangles is 900 sq. in.

Find the area of the 3 rectangles A = LW

1st rectangle and 2nd rectangle

a = cb

a = (30 in) (14 in)

a = 420 sq in. (make sure you add this again in the Total Surface area)

3rd rectangle

a = ab

a = (45 in) (14 in)

a = 630 sq. in

Total Surface area = 2 (1/2 ad) + 2(cb) + (ab)

= 2 (450 sq. in) + 2 (420 sq. in) + 630 sq. in

= 900 sq. in + 840 sq. in + 630 sq. in

= 2370 sq. in