In Fig 10.57, a circle is inscribed in a quadrilateral ABCD in which . If AD = 23 cm, AB = 29 cm and DS = 5 cm, find the radius r of the circle.
AD = DS = 5cm (tangent from an external point)
Since AD=23 cm
So,
AR + RD + AD
AR + 5 = 23 cm
AR = 18 cm ------(i)
and AQ = AR
since AR = 18 cm
So, AQ + QB = AB
Now OP and OQ are radius of the circle. So from tangent P and Q