JAMB - Mathematics (1985 - No. 43)
In the figure POQ is the diameter of the circle PQR. If PSR = 145o, find xo
25o
35o
45o
125o
55o
解释
< PRQ = \(\frac{1}{2}\) < POQ = 90o
< PSR + < PQR = 180o
< PQR = 180o - 145o = 35o
\(\bigtriangleup\)PQR is a right angled triangle
x = 90 - < PQR
= 90o - 35o
= 55o