Complete the square on this to put it into vertex form. When you do that you get an equation that looks like this: h(t)= -9.8(t-1.5)^2 + 82.05 Assuming you know something about that equation, the vertex is (1.5, 82.05) which gives you your time value of 1.5 seconds, and the max height value of 82.05. So the max height is 82.05 m and it reaches that height at 1.5 seconds.
