Respuesta :

Answer:

81.75 ft²

Step-by-step explanation:

The area (A) of a trapezoid is calculated using the formula

A = [tex]\frac{1}{2}[/tex] h (a + b)

where a, b are the parallel bases and h is the perpendicular height

Calculate h using the right triangle and the sine ratio

sin30° = [tex]\frac{opposite }{hypotenuse}[/tex] = [tex]\frac{h}{10}[/tex]

Multiply both sides by 10

10 × sin30° = h, thus

h = 5

a = 12 and b = 8.7 + 12 = 20.7, hence

A = [tex]\frac{1}{2}[/tex] × 5 × (12 + 20.7)

   = 0.5 × 5 ×32.7

   = 81.75 ft²