Question

plz help me
tell me answer immediately plz​

Answer 1

$\bold \red{Answer }$

In △ABD,

AB²=BD²+AD² (Pythagoras theorem)

In △ACD,

AC²=CD² +AD² (Pythagoras theorem)

Add both the equations,

AB²+AC²=BD²+AD²+CD²+AD²

BC²=BD²+AD²+2BD×CD−2BD×CD+2AD² (Apply pythagoras theorem to triangle ABC)

BC²=(BD+DC)²−2BD×CD+2AD²

BC²=BC²−2BD×CD+2AD²

AD²=BD×CD