1) For number 1, you want to find the area of the square and the circle, then subtract: Area of square - area of circle. That will give you the area of the shaded region.
Area of square: 8² = 64, Area of circle: π4² = 50.27
64 - 50.27 = 13.73 ft²2)
For number 2, subtract the area of the rectangle by the area of the traingle.
Area of rectangle: (10)(6) = 60, Area of triangle:
= 21
60 - 21 = 39 in²3) For number 3, you could either find the entire rectangle and the empty space, and subtract the rectangle by the empty space, or cut the rectangle into sections and find each of the sections, then add them up. I'm going to find the entire rectangle then subtract it by the empty space. I think the problem is set up to be easier that way.
Area of rectangle: (12)(8) = 96, Area of empty space: (4)(4) = 16
96 - 16 = 80 in²
4) Find the area of the rectangle and the area of the semicircle. Subtract the rectangle by the semicircle.
Area of rectangle: (13)(6) = 78, Area of semicircle: π3² / 2 = 14.14
78 - 14.14 = 63.86 yd²