I need help on how to do these 3 questions

Step-by-step explanation:

In each case, you find the lateral area by finding the area of one triangular face and multiplying that by the number of same-size faces.

You find the base area by multiplying its dimensions. (The base area is given for problem 3, so use that.)

The total surface area is the sum of the base area and the lateral area.

The formula for the area of a triangle is ...

  A = (1/2)bh

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1) triangle area = (1/2)(9 in)(11 in) = 49.5 in^2

  lateral area = 4 × triangle area = 4×49.5 in^2 = 198 in^2

  base area = (9 in)(9 in) = 81 in^2

Total surface area = 198 in^2 + 81 in^2 = 279 in^2

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2) Same idea. Since we know the lateral area is 4 times the triangle area, we can compute the lateral area directly.

  lateral area = 4(1/2)bh = 2bh = 2(24 ft)(18 ft) = 864 ft^2

  base area = (24 ft)(24 ft) = 576 ft^2

Total surface area = 864 ft^2 +576 ft^2 = 1440 ft^2

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3) lateral area = 3(1/2)(8 cm)(15 cm) = 180 cm^2

Total surface area = 180 cm^2 +27.7 cm^2 = 207.7 cm^2

it has to be a.

you should at least use a calculater

step-by-step explanation: