Home » In the given diagram, (bar{QT}) and (bar{PR}) are straight lines,

In the given diagram, (bar{QT}) and (bar{PR}) are straight lines,

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.
35^o
B.
40^o
C.
55^o
D.
60^o

Correct Answer: Option 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°