The perimeter of a semicircle consists of two parts. (the curve and bottom)
That curve is half the distance around the circle, since it's been split in half.
The distance around a circle, the circumfrence, is equal to 2πr, where r is the radius of that circle. In this case, the circumfrence of the entire circle would be 16π. and so that curve would have a length of just 8π.
Using 3.14 for π, 8π = 8×3.14 = 25.12.
As for the flat part, that is the diameter (distance across) our circle.
The radius is the distance from the center of a circle to its edge, and always has half the length of the diameter. (you can break the diameter down into two radii)
If our radius is 8 meters, our diameter (the flat part of that semicircle) must be 16.
Now we add up the two parts of the perimeter...25.12 + 16 = 41.12.
Y = 2x
y = 2*(-15) = -30 . . . . . selection A is appropriate
*use calculator to get final product
*x is not equal to 13.490 it is an estimation so use (≈)
The perimeter is the total of adding all of the sides together. A rectangle has 2 lengths and 2 widths. The equation would be:
P = 2l + 2w or P = l + l + w + w
Since you know the perimeter, you can plug it into the equation
53 = 2l + 2w
You can divide the 2 on both sides
26.5 = l + w
l = w + 2.3 because the length is 2.3 meters longer/more than the width. You can substitute (w + 2.3) for "l" in the equation. So instead of:
26.5 = l + w
It will be:
26.5 = (w + 2.3) + w
26.5 = w + 2.3 + w
Subtract 2.3 on both sides
24.3 = w + w
24.3 = 2w
Divide 2 on both sides
12.1 = w
The width is 12.1 meters
Answer:
I'm pretty sure you can find the whole answer book online
