Each of the base angles of a isosceles triangle is 58^\circ and the verticles of the triangle lie on a circle. Determine the angle which the base of the triangle subtends at the centre of the circle.
A
128o
B
16o
C
64o
D
58o
Verified Correct Answer: A.
Step-by-Step Mathematical Solution
Base angle of the triangle = 58^\circ.
The third angle = 180^\circ - (58^\circ + 58^\circ)
= 64^\circ
Angle subtended at the centre = \(2 \times 64^\circ = 128^\circ\) (angle at the centre is twice the angle at the circumference).
Source: Myschool Past Questions Archive (Record #30822)