In the given diagram, \(\bar{QT}\) and \(\bar{PR}\) are straight lines, < ROS = (3n - 20), < SOT = n, < POL = m and < QOL is a right angle. Find the value of n.
A. 35o B. 40o C. 55o D. 60o
Correct Answer: A
Explanation
In the diagram, QOR + 2m(vertically opposite angles) So, m + 90° + 2m = 180° (angles on str. line) 3m = 180° - 90° 3m = 90° m = \(\frac{90^o}{3}\) = 30° substituting 30° for m in 2m + 4n = 200° gives 2 x 30° + 4n = 200° 60° + 4n = 200° 4n = 200° - 60° = 140° n = \(\frac{140°}{4}\) = 35°
