I think that the best answer here would be that A = 40 degrees.
A stuntman jumping off a 20-m-high building is modeled by the equation h = 20 – 5t2, where t is the time in seconds. A high-speed camera is ready to film him between 15 m and 10 m above the ground. For which interval of time should the camera film him?
Answer:

Step-by-step explanation:
Given:
A stuntman jumping off a 20-m-high building is modeled by the equation
-----------(1)
A high-speed camera is ready to making film between 15 m and 10 m above the ground
when the stuntman is 15m above the ground.
height
Put height value in equation 1





We know that the time is always positive, therefore 
when the stuntman is 10m above the ground.
height
Put height value in equation 1







Therefore ,time interval of camera film him is 
Answer:
The answer would be 0.00000007
Jennifer
1. 6
2.26
3.42
4.82
erika
1.7 (erika wrong)
2.15 (right)
3.23 (right)
4.43 (right)
6a. 6 is the right one
2(6+2)-7=9
The answer is C i believe