WAEC - Mathematics (2010 - No. 43)

3x = 2 x 60 = 2y (Angle at centre = 2 x angle at circumference)

3x = 2 x 60

x = \(\frac{2 \times 60}{3}\) = 40^o

2 x 60 = 2y

y = 60^o

x + y = 40 + 60

= 100^o