Equilateral Triangle

Last updated at April 16, 2024 by

In equilateral triangle,

  • All sides are equal
  • All angles all equal 60°

In equilateral ∆ ABC,

  • AB = AC = BC
  • ∠A = ∠B = ∠C = 60°

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But, why are all angles 60°?

In equilateral triangle, all angles are equal.

Let ∠A = ∠B = ∠C = x

Equilateral Triangle - Part 2

In ∆ABC

Sum of angles is 180°

  ∠A + ∠B + ∠C = 180°

  x + x + x = 180° 

  3x = 180°         

  x = (180°)/3

  x = 60°

 

So, ∠A = ∠B = ∠C = 60 °

Thus, all angles are 60°    

 

For equilateral triangle

Equilateral Triangle - Part 3

Perimeter = 3a

Check proof  

 

Area = √3/4 a 2

Check proof  

 

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Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.