This looks like gobbledygook, tell us what you are trying to do and why.Distance = 80m, Time = 1.67 seconds
Upper height of target = 1.8m - 0.6m = 1.2m
Lower height of target = 1.8m + 0.6m = 2.4m
distance = rate*time
80m = rate*1.67 seconds
rate = 48m/s
then using t = 1.67 seconds, and v = 48m/s
48sin(theta)(1.67) - 5(1.67)^2 = 1.2m
theta = 10.87 degrees
48sin(theta)(1.67) - 5(1.67)^2 = 2.4m
theta = 11.79 degrees
I am not sure if this is the right way to do this question.
Also what course is this set as homework for, you have posted it Pre-Algebra and Algebra. If so you must have been given some background information that we don't have.