A Hooked Drive
Part of the Triangles Without Right Angles section of Coddy's Trigonometry journey. Lesson 19 of 44.
A golfer drives from the tee T toward a hole H 220 m away. The ball flies 200 m but leaves the line by 10°. How far is the ball B from the hole? A quick guess says 220 − 200 = 20 m. The triangle says otherwise.
The two sides from the tee meet at 10°, so d^2 = 220^2 + 200^2 - 2×220×200×cos(10°) and d is about 41.68 m, twice the guess. In a thin triangle a small angle still opens a wide gap far from the corner.
Challenge
The hole H is 250 m from the tee T. A drive goes 230 m but 8° off the line to the hole. Find the distance x from the ball to the hole, to two decimal places, and press Check.
Try it yourself
Use the figure to find x
Test yourselfThis lesson includes a short quiz. Start the lesson to answer it and track your progress.
All lessons in Triangles Without Right Angles
4Law of Cosines: SAS
The Law of CosinesAn Obtuse Angle BetweenThrough the HillA Hooked DriveRecap: Two Sides, One Angle2Law of Sines: AAS and ASA
Why the Law of Sines HoldsPair Side With AngleThe Third Angle FirstTwo Coast StationsRecap: Law of Sines8Bearings and Navigation
Reading BearingsTwo Ships From PortTurning Off CourseFinding a Course AngleRecap: Ships at Sea