Answer:
1 seconds after being thrown, the stone reaches its max height
Step-by-step explanation:
The parabolic (quadratic) equation is:

Lets expand this in the form
, so we have:

We can say the values of a,b, and c, now to be:
a = -5
b = 10
c = 40
The number of seconds at which the max would occur is given by the point, x, at:

We know a and b, let's find the seconds, x,

Hence,
1 seconds after being thrown, the stone reach its max height
One lap. Usually, it would take 4 laps to walk a mile, but since its 1/4 it equals One lap.
Acute because it is less than 90 degrees
Answer:
Angle B
Step-by-step explanation:
To find the smallest angle it is the opposite of the smallest side in the triangle in this case as all sides are given.