Answer:
x = 6 ft
Explanation:
Area of the polygon = area of the square + 2(area of the triangle)
Area of the polygon = 176 ft²
Area of the square = length × width = 16 × 8 = 128
Area of the two triangles = 2(½*base*height) 2(½*x*8) = 8x
Plug in the above values into the equation for area of the polygon. Thus:
176 = 128 + 8x
Subtract 128 from each side
176 - 128 = 8x
48 = 8x
Divide both sides by 8
6 = x
x = 6 ft