Question

Each side of an equilateral triangle measures $10\text{cm}$. Its area is __________.

• A. $25\sqrt{3}{\text{cm}}^2$
• B. $25\sqrt{2}{\text{cm}}^2$
• C. $50{\text{cm}}^2$
• D. $30{\text{cm}}^2$

Answer 1

Answer: (A)

$25\sqrt{3}{\text{cm}}^2$

Given, side of an equilateral triangle $=a=10cm$

Area of equilateral triangle of side '$a$' is given by,

$A=\frac{\sqrt{3}{a}^2}{4}$

$=\frac{\sqrt{3}\times {10}^2}{4}{\text{cm}}^2$

$=25\sqrt{3}{\text{cm}}^2$