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Areas Of Parallelograms And Triangles

Question
CBSEENMA9002601

In an isosceles triangle ABC with AB = AC, BD and CE are two medians. Prove that BD = CE. 

Solution

Given: In an isosceles triangle ABC with AB = AC, BD and CE are two medians.
To Prove: BD = CE

Proof: In ∆ABC,
∵ AB = AC
∴ ∠BC = ∠ACB    ...(1)
| Angles opposite to equal sides of a triangle are equal
Also,  1 half AB equals 1 half AC

| Halves of equals are equal ⇒ BE = CD    ...(2)

| ∵ BD and CE are two medians
Now, in ∆BDC and ∆CEB,
∠BCD = ∠CBE    | From (1)
BE = CD    | From (2)
BC = CB    | Common
∴ ∆BDC ≅ ∆CEB
| SAS congruence rule
∴ BD = CE    | CPCT