Question

Find the lateral area, and surface area of the figure.

Answer 1

Answers:

• Lateral Area = 108 square km
• Surface Area = 120 square km

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Explanation:

Think of the triangles as the floor and ceiling of this 3D room. The walls are the three rectangular sides.

We have a 9 by 4 wall with area 9*4 = 36 square km

We have a 9 by 3 wall with area 9*3 = 27 square km

We have a 9 by 5 wall with area 9*5 = 45 square km

The lateral area is 36+27+45 = 108

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The two triangles form the base faces of this prism.

Let's find the area of one of the triangles

area = 0.5*base*height = 0.5*3*4 = 6

One triangle has area 6, so both triangles in total have area 2*6 = 12 square km.

The total surface area is therefore 108+12 = 120 square km