In the given figure, a circle is inscribed in the quadrilateral ABCD. Given AB = 6cm, BC = 7cm and CD = 4cm. Find AD.
We know that
Lengths of tangents drawn from external point are equal
Thus,
AP = AS
BP = BQ
CR = CQ
DR = DS
Adding (1) + (2) + (3) + (4)
AP + BP + CR + DR = AS + BQ + CQ + DS
(AP + BP) + (CR + DR )= (AS + DS ) + (BQ + CQ)
AB + CD = AD + BC
Putting AB = 6cm, BC = 7cm and CD = 4cm
6 + 4 = AD + 7
10 = AD + 7
10 − 7 = AD
AD = 3 cm
Made by
Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 12 years. He provides courses for Maths and Science at Teachoo.