Question

90 POINTS! HELP ASAP! Using one of the figures below, explain a strategy for calculating the area of the irregular polygon.

Answer 1

The area of the irregular polygon:

88 units²

Explanation:

The irregular polygon is insert in a rectangle

The strategy is:

1 - calculate the rectangle total area

2- calculate the area of each right triangle

3.- substracte the total area of the 4 right triangles from the area of the rectángule

then:

1.-

Ar = 12*11 = 132 units²

Ar = rectangle area

2.-

At₁ = (5*5)/2 = 25/2 = 12.5 units²

At₂ = (6*3)/2 = 18/2 = 9 units²

At₃ = (7*3)/2 = 21/2 = 10.5 units²

At₄ = (8*3)/2 = 24/2 = 12 units²

At total = 12.5 + 9 + 10.5 + 12 = 44 units²

At = right triangle areas

3.-

Ap = 132 - 44 = 88 units²

Answer 2

area of polygon = 88 sq. units

Explanation:

lets make it simple, short and accurate.

area of polygon = total area - total area of triangles

total area = 11 * 12 = 132

triangle 1 = 1/2 * 5 * 5 = 12.5

triangle 2 = 1/2 * 3 * 6 = 9

triangle 3 = 1/2 * 3 * 8 = 12

triangle 4 = 1/2 * 3 * 7 = 10.5

total area of triangle = 12.5 + 9 + 12 + 10.5 = 44

area of polygon = 132 - 44 = 88 sq. units