The answer to your question is y=-5
The ball hits the ground when the height h(t) = 0 , so
-16t^2 + 80t = 0
-16t(t - 5) = 0
t- 5 = 0 or -16t^2 = 0 ( here t = 0 which corresponds to when ball is thrown)
t - 5 = 0 gives:-
t = 5 seconds (answer)
The perimeter should be about 66
Answer:

Step-by-step explanation:
1) Use square sum: (a + b)² = a² + 2ab + b².

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