Please help. I don't how to do it

At a point on the ground 50 meters from the foot of a tree, the angle of elevation to the tree is 48°. find the height of the tree to the nearest meter.

Acircle has a circumference of 28.36 units what is the diameter of the circle

Suppose that 3% of all athletes are using the endurance-enhancing hormone epo (you should be able to simply compute the percentage of all athletes that are not using epo). for our purposes, a “positive” test result is one that indicates presence of epo in an athlete’s bloodstream. the probability of a positive result, given the presence of epo is .99. the probability of a negative result, when epo is not present, is .90. what is the probability that a randomly selected athlete tests positive for epo? 0.0297