Question

if two isosceles triangle have a common base.prove that the line joining that vertices bisects the base at right angle​

Answer 1

Your answr is in the picture friend :)

Answer 2

.Too prove=AD bisects BBC at right angles

Proof=2N ∠ A B C a n s ∠ A D C ∠ABCans∠ADC AB

=AC(given) BD

=CD(given) BC=BC(common)

∠ A B C ≅ ∠ A D C ( S S S )

∠ABC≅∠ADC(SSS) ∠ 1 = ∠ 2 ∠1

=∠2 I n ∠ A B E and ∠ A C E In∠ABEand∠ACE AB

=AC ∠ a = ∠ 2 ∠a=∠2 AE=AE(common) ∠ A B E ≅ ∠ A C E ( S A S )

∠ABE≅∠ACE(SAS) BE=CE ∠ 3

= ∠ 4 ∠3=∠4 ∠ 3 + ∠ 4 = 180 ∘ ∠3+∠4=180∘ 2 ∠ 3

= 180 ∘ 2∠3=180∘ ∠ 3 = 90 ∘ ∠3=90∘.