In the diagram, o, o and o. Calculate the obtuse angle QRS.
Attached Figure / Diagram
A
90o
B
100o
C
121o
D
60o
Verified Correct Answer: C.
Step-by-Step Mathematical Solution
Joining SQ. In \(\bigtriangleup\) SPQ,
(22o + a) + 55o + (41o + b) = 180o
121o + a + b = 180o
a + b = 180 - 121
a + b = 59o.....(1)
In \(\bigtriangleup\) SRPQ; R + a + b = 180o
R + 59o = 180o
(in (1), a + b = 59o)
R = 180 - 59
R = 121o
Source: Myschool Past Questions Archive (Record #36598)