1. find the area of the regular polygon to the nearest tenth.

square with a radius of 13 m

a) 344 m²
b) 676 m²
c) 169 m²
d) 338 m²

2. find the area of the triangle give the answer to the nearest tenth. the drawing may not be to scale.

(see picture attached)

a) 47.4 cm²
b) 94.8 cm²
c) 7.5 cm²
d) 303.1 cm²

Step-by-step explanation:

You can use the same formula in each case. The area of a triangle with sides "a" and "b" separated by angle α is ...

  A = (1/2)ab·sin(α)

1. The area of the square is 4 times the area of the right triangle whose legs are radii of the square:

  square area = 4·(1/2)·(13 m)(13 m)sin(90°) = 2·(13 m)² = 338 m²

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2. The area is ...

  A = (1/2)(8 cm)(12 cm)sin(81°) ≈ 47.4 cm²

For this one, you don't need to work out the answer in detail. You know it will be less than, but nearly, 48 cm², which is half the product of the side lengths.

diameter = 5

the diameter is twice the radius

diameter = 2.5 × 2 = 5