# Each side of an equilateral triangle is 10 cm long.

Question:

Each side of an equilateral triangle is 10 cm long. The height of the triangle is

(a) $10 \sqrt{3} \mathrm{~cm}$

(b) $5 \sqrt{3} \mathrm{~cm}$

(c) $10 \sqrt{2} \mathrm{~cm}$

(d) $5 \mathrm{~cm}$

Solution:

(b) $5 \sqrt{3} \mathrm{~cm}$

Height of equilateral triangle $=\frac{\sqrt{3}}{2} \times$ Side

$=\frac{\sqrt{3}}{2} \times 10$

$=5 \sqrt{3} \mathrm{~cm}$