Answer:
37
Step-by-step explanation:
all triangles have a total of 180 degrees
set up equation and solve
180=(2x+4)+(2x-9)+x
180=5x-5
185=5x
37=x
Let the middle child be x
youngest child = x - 1
Oldest child = x + 1
(x - 1)^2 = 8(x + 1) + 4
x^2 - 2x + 1 = 8x + 8 + 4
x^2 - 10x - 11 = 0
(x - 11) * (x + 1) = 0
X = - 1 makes no sense. How can a middle child be - 1 years old?
x = 11
The youngest child is 10
The middle child is 11
The oldest child is 12
Check
=====
10^2 = 100
(8*12) + 4
96 + 4 = 100 So the results have been checked.
Answer:

Step-by-step explanation:
The standard equation of a straight line is of the form:

We have to convert the given equation into above form.
Simplifying the given equation:


.- This is in standard form
where 
First find the perimeter. Then take the depth of the pool and multiply it by the perimeter.
Hope this helps