The incircle of ΔABC touches the sides BC, CA and BA at D, E and F respectively. If
AB = AC, prove that BD = CD.
A quadrilateral ABCD is drawn to circumscribe a circle (Fig. 10.62). Prove that AB + CD = AD + BC.
DR = DS
RC = CQ [Using above theorem]
BQ = PB
AP = AS
⇒ DS = 4 cm, because DR = 4 cm
RC = CQ = 3 cm
PB = BQ = 5 cm
AS = AP = 6 cm
⇒ Perimeter of ABCD quad.
= AB + BC + CD + AD
= AP + PB + BQ + CQ + CR + DR + AS + SD
= 2(DR + CQ + PB + AD)
= 2(18) = 36 cm.