Question

In the given figure, a circle touches all the four sides of quadrilateral $ABCD$ whose three sides are $AB=6cm,BC=7cm$ and $CD=4cm$. Find $AD$ (in cm).

Answer 1

Consider the following question.

Let P, Q, R and S are the touch point of quadrilateral.

Hence,

AP=AQ, DP=DS, BQ=BR and CS=CR

Adding,

$AP+\text{CS}+DS\text{+}DP=AQ+\text{DC+BR+CR}$

$\text{AD+CD}=AB+BC$

$AD+4=6+7$

$AD=9cm$

Hence, this is the required answer.