Question:
In the given figure, if AB = AC, prove that BE = CE.
Solution:
Given, $A B=A C$
We know that the tangents from an external point are equal.
$\therefore A D=A F, B D=B E$ and $C F=C E \ldots \ldots . .(i)$
Now, $A B=A C$
$\Rightarrow A D+D B=A F+F C$
$\Rightarrow A F+D B=A F+F C \quad[$ from $(\mathrm{i})]$
$\Rightarrow D B=F C$
$\Rightarrow B E=C E \quad[$ from (i) $]$
Hence proved.