Robin Hood is helping you practice and tries to show you need math to be a good archer.
Robin start off with a target that's 7 feet away from him ,and 5 feet above his point of aim.He must find find the correct angle he must aim from.To find this angle he uses trigonometry. He determines his needed angle for the shot is tan-1 (5/7)=81.9 degrees
Robin Hood is now up on a hill perpendicular to the horizontal axis of the target.The hill sets him 3 feet above the target.His angle of depression towards the target measures 54 degrees. By using trigonometry(3/cos(54)),he determines he is 5.1 feet away.
Even though it was dark and Robin Hood couldn't see as well, he knew that if he used math correctly he would still be able to land his shot.He knew the target was 9 feet above his shooting point and that his arrow would travel 15 feet.Now like his first shot he need to find the angle of elevation.He knows that since he has the opposite side and hyp. he has to use sine. He determines that his angle is sin-1 (9/15) which equals 36.9 degrees.
Now you see that math is needed even in archery.THE END.