Question

What is the length of an altitude of an equilateral triangle of side 'a' units.

• A. $\frac{a}{\sqrt{3}}$
• B. $\frac{a}{\sqrt{2}}$
• C. $\frac{a}{2}$
• D. $\frac{\sqrt{3}a}{2}$

Answer 1

The correct option is D $\frac{\sqrt{3}a}{2}$

$In△AMB:$

$sin60=\frac{AM}{AB}$

$⟹\frac{\sqrt{3}}{2}=\frac{AB}{a}$

$⟹AB=\frac{\sqrt{3}a}{2}$