I can't see the pages to be able to help you sorry
Use the midpoint formula
(x1 + x2/2, y1 + y2/2)
Input the corresponding numbers
(-12 +5/2, 3 + -10/2)
(-7/2,-7/2)
So, the midpoint of the line segment is (-7/2,-7/2)
We can let the radius of the semi circles be r and x can be the length of the rectangle.
The perimeter will be Perimeter = 2x + 2pr = 1200
The area of the rectangle is Area = x(2r)
Once we solve the perimeter equation, you get x = 600.
Put this into the area equation and you get Area = (600 - pr)(2r)
The maximum then gives r = 95. 493 and area 57, 295.8
Dimensions
Height is twice the radius or 190.986. Find base use equation x = 600 - p(95.493) = 300.
This means dimensions are 300 by 190.986
Take 14,350 x .28 = 4,018 of them were high school students
The total attended were 14,350 people. 28% of them were high school students, so it's a simple multiplication problem to find the number of high schoolers.