Question

please solve the question class 10 triangles

Answer 1

we have to prove , BC²=4(AD² - AB²)

BD = DC (D is the midpoint)

BD²=AD²- AB²

DC²=AD² - AB²

because BD=DC

BC=BD+DC

BC²=BD²+DC²

Therefore, BC²=(AD² - AB²) + (AD²-AB²)

BC²=AD²-AB²+AD²-AB²

=2AD²-2AB²