Question

the area of equilateral triangle of side40cm is
$a) 100 \sqrt{6 \: cm} {}^{2}$
$b)160 \sqrt{3} cm {}^{2}$
$c) \: 200 \sqrt{3} cm {}^{2}$
$d)400 \sqrt{3cm {}^{2} }$

Answer 1

Area of equilateral triangle =root3/2×a2
=root3×800
=800root3

Answer 2

Here a=40cm
area of equilateral ∆=
$( \sqrt{3} \div 4)a {}^{2}$
$( \sqrt{3 } \div 4) \div (40cm) {}^{2}$
$\sqrt{3} \times 400cm {}^{2}$
$400 \sqrt{3cm {}^{2} }$