a)
First one is a rectangle with two semicircles removed, which we can think of as one whole circle.
The rectangle dimensions are 14m by 15m
The circle has a diameter of 14m - 2m - 2m = 10m. So it has radius 5m.
Of course the area of a rectangle is length times width and the area of a cricle is πr²
So the area we seek is
A = 14×15 - π(5²) = 210 - 25π
Answer: 210-25π sq meters
You didn't ask for an approximation so we'll leave it exact. You'll have to work the calculator if they want an approximation.
b)
Ugh. That's a parallelogram less a rectangle and a right trapezoid, with a semicircle put back in.
Parallelogram base 20 m, height 15 m. I'm going to leave out the units for now. Area is 20×15.
Rectangle (at bottom) 4 by (20 - 6 - 3) is 4 by 11. Area is 4×11.
Trapezoid height 8, bases 11 and 6. Area is 8(11 + 6)/2
Semicircle, diameter 8, radius 4. Area is π4²/2.
A = 20×15 - 4×11 - 8(11 + 6)/2 + π4²/2
A = 188 + 8π square meters
Answer: 188+8π sq meters
Again I leave any calculator work to you.
