8.(ii) In right triangle ABC, right angled at C, M is the mid-point of hypotenuse AB. C is joined to M and produced to a point D such that . Point D is joined to point B (see Fig.). Show that:
(ii) is a right angle.
In the previous part, we have proved that .
By c.p.c.t. we can say that :
This implies side AC is parallel to BD.
Thus we can write : (Co-interior angles)
and,
or
Hence is a right angle.