In the diagram, < PSR = 220o, < SPQ = 58o
In the diagram, < PSR = 220o, < SPQ = 58o and < PQR = 41o. Calculate the obtuse angle QRS.
A.
90o
B.
100o
C.
121o
D.
60o
Correct answer is C
Joining SQ. In △ SPQ,
(22o + a) + 55o + (41o + b) = 180o
121o + a + b = 180o
a + b = 180 - 121
a + b = 59o.....(1)
In △ SRPQ; R + a + b = 180o
R + 59o = 180o
(in (1), a + b = 59o)
R = 180 - 59
R = 121o