Question

Can you help explain please? I’m kind of in a crunch

Answer 1

The first thing you need to do is find the radius of the semicircle. To do that you look to see that the width of the rectangle is the same as the radius. Once you have the Area of a Semicircle calculated multiply it by 3. then, we know that the other length of the rectangle is 3 diameters of a semicircle this means that you multiply the radius of 7 by 6 which gives you 42. You take the area of the rectangle (294) and subtract the area of the 3 semicircles(230.79) Which gives you the answer of 63.21cm^2

Answer 2

The 7 cm side of the rectangle also serves as the radius of the circle

The problem wants us to take the area of the rectangle and subtract it by each of the 3 semicircles

The area of a full circle is:

$\pi {r}^{2}$

SEMICIRCLE:

So the area of a semicircle is half of that:

$\frac{\pi {r}^{2} }{2}$

All 3 of these semicircles have the same area so once we find the area of one, all we have to do it multiply it by 3:

$\frac{\pi {r}^{2} }{2} \\ \frac{3.14 \times ( {7})^{2} }{2} \\ 3.14 \times {3.5}^{2} \\ 38.465$

The area of one semicircle is 38.465 so 3 of them would be 115.395cm

RECTANGLE:

The area of a rectangle is equal to length • width

The width is given as 7cm and we can find the length by remembering that the radius of each semicircle is 7cm and since there are 3 semicircles we know the length of the rectangle is 21 cm

Making the area of the rectangle 7cm • 21cm which equals 147cm

Now we take 147cm and subtract it by 115.395cm and we are left with 31.605cm^2 I believe

My Best Guess: 31.605cm ^2