Q. 6. In the adjoining figure, if LMPCB and LNPCD prove that 
OR
In the adjoining figure, if 
Q. 7. In the adjoining figure, XP and XQ are two tangents to a circle with centre O from a point X outside the circle. ARB is tangent to circle at R. Prove that
XA + AR = XB + BR.
Q. 8. In the adjoining figure, XY and ST are two parallel tangents to a circle with centre O and another tangent AB with point of contact C is intersecting XY at A and ST at B. Prove that Ð AOB = 90º
