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I need help plzzzz!!!!!! find the area

I need help plzzzz!!!!!! find the area-example-1
User Nerijus G
by
9.2k points

2 Answers

5 votes

Answer:

area = 387 ft^2

3 bags

Explanation:

See the picture below.

The pentagon is made up of 5 congruent triangles. One triangle is shown on the bottom right figure.

The left figure shows half of the triangle. We need to find h, the height of the triangle.

For a regular pentagon, the measure of each interior angle is

(n - 2)180/5 = 108

Half of the angle is 54 deg.

tan A = opp/adj

tan 54 = h/7.5

h = 7.5 * tan 54

h = 10.32 ft

Area of half triangle = bh/2 = 7.5 ft * 10.32 ft/2 = 38.7 ft^2

The pentagon is made up of 5 larger triangles or 10 half triangles.

Area of pentagon = 10 * 38.7 ft^2

Area of pentagon = 387 ft^2

1 bag is good for 150 ft^2.

387 ft^2/150 ft^2 = 2.6

She needs 2.6 bags, so she must buy 3 bags.

Answer: 3 bags

I need help plzzzz!!!!!! find the area-example-1
User Pollux
by
7.8k points
3 votes

Answer:

3

Explanation:

Area = 1/4 * √(5(5+2√5)) * a^2

Area ≈387.11

because each bag only covers 150 we need 3 bags

User Thrinadhn
by
7.5k points

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