passwella.
Menu

WAEC Further Mathematics 2009 Question 21

Question 21

Trigonometry

In the diagram, a ladder PS leaning against a vertical wall PR makes angle x° with the horizontal floor. The ladder slides down to a point QT such that angle QTR = 30° and angle SNT = y°. Find the relation between x and y

Diagram for this question
  1. A.y = ½x + 30
  2. B.y = ½x − 30
  3. C.y = x + 30
  4. D.y = x − 30
Show the answer and explanation

Answer: D (y = x − 30)

Explanation

In triangle NST, angle NST = 180° − x and angle NTS = 30°, so y = 180° − (180° − x) − 30° = x − 30°.