Angle subtended by a chord on the centre of a circle is 180 degree. What will be the angle subtended by the same chord on the circumference of this circle?

When a chord subtends 180° at the center, it is a diameter. According to the theorem: 'The angle subtended by a chord at the center is twice the angle subtended at the circumference on the same side.' Therefore, if the central angle is 180°, the angle at the circumference = 180°/2 = 90°. This is a fundamental property of circles.