Mathematics
If two altitudes of a triangle are equal, prove that it is an isosceles triangle.

Triangles
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Answer
Given,
CE = BD [Altitudes of △ABC are equal]
In △ABD and △ACE,
⇒ ∠ADB = ∠AEC [Each equal to 90°]
⇒ CE = BD [Given]
⇒ ∠DAB = ∠EAC [Common angle]
∴ △ABD ≅ △ACE (∵ A.A.S. axiom)
⇒ AB = AC [Corresponding parts of congruent triangles are equal]
Since, two sides are equal.
Hence, △ABC is an isosceles triangle with AB = AC.
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