Question

In the given figure, A A ABC is
an isosceles triangle in which
AB = AC. If A = 40, then find the
values of x and y
​

Answer 1

Answer:

ANSWER

REF.image

To prove : AB×EF=AD×EC

⇒

EC

AB

=

EF

AD

Proof :

AB=AC (∵ ABC is isosceles)

∴∠B=∠C (angles opposite to equal sides are equal) - (1)

In ΔABD and ΔECF

∠ABD=∠ECF (from (1))

∠ADB=∠EFC (Both are 90

∘

)

Using AA similarity

ΔADB∼ΔECF

⇒

EC

AB

=

EF

AD

⇒AB×EF=AD×EC

∴ Hence proved.

solution

Answer 2

Answer:

40+angleb+anglec=180

angle b+c=180-40

angle b+c=140

2b=140

b=140÷2

=70

c=70

x=180-70

x=110

y=180-70=110

hope this helps