Question

using congruency of triangles prove that the base angles of an isosceles triangle are equal.​

Answer 1

Step-by-step explanation:

join A to P perpendicular to base bc

we know that in isosceles triangle two sides are equal

so,AB =AC

to prove: base angle of an isoscles ∆ are equal

proof: in ∆ABP and ∆ACP

AB =AC ( sides of an isoscles triangle )

AP=AP (common)

angle ABP = angle ACP

hence,∆ABP congurence to

∆ACP

angle ABP = angle ACP (by cpct )

so,the base angles of isosceles triangle are equal

proved