I think it's 7 hope its right sorry if not
20 of the students would be 6th graders, hope that helps!
If you look at the rectangle properly, you can see that the diagonal creates two triangles, and if we only focus on one triangle, we can see that the bad of the triangle is 7 and the perpendicular height is 4
Using Pythagorean theorem we can figure out the hypotenuse, or the diagonal
C squared is equal to a squared plus b squared
7^2+4^2 is 65
Square root of 65 is 8.1
Answer:
The slope is -2
Step-by-step explanation:
Since the roof is decreasing in height as it goes forward, I know that the slope must be negative. The equation to find the slope is rise/run. The vertical change, or the rise, is -6 feet, so that value goes on top of the fraction. The horizontal value, or the run, is 3 feet so that goes on the bottom of the fraction.
Now our fraction is 
If you simplify that fraction, you'll get -2.
We have that

we know that
Is the equation of a vertical parabola open down
so
the vertex is a maximum
step 1
convert the equation of the parabola in the vertex form

the vertex (h,k) is the point (0,36)
Part a) The point on the graph where the height of the tunnel is a maximum is (0,36)
Part b) The points on the graph where the height of the tunnel is zero feet is when y=0
so
for y=0

the points are (-6,0) and (6,0)
see the attached figure