Correct Answer - Option 4 : 2√3a cm
Calculations:
All sides of an equilateral triangle are equal.
Sum of three perpendiculars of an equilateral triangle = height of triangle
Height of triangle = a cm
Side of an equilateral triangle = 2/√3 × a
∴ Perimeter of an equilateral triangle = 3 × 2a/√3 = 2√3a cm.
For equilateral triangle: The sum of all the three lengths = height of equilateral triangle