6. The course at a motocross competition is to be triangular. The first two legs are to be 147 m and 213 m long, joining at an angle of 84 a) b) Design a plan to determine the angle measurements the riders need to turn through at the other two corners. Use your plan to calculate these angles. 7.. An air traffic controller is tracking two airplanes. The first airplane is due west 18.4 km from the tower, at an angle of elevation of 49. The second airplane is due east, 16.3 km from the tower, at an angle of elevation of 43. How far apart are the airplanes to the nearest tenth of a kilometre? Lesson 3: Project Page 6