Question

show that ABC is an equilateral triangle If a,b,c have the coordinates a(1,√3) b(3,√3) c(2,2√3)

Answer 1

By distance formula, find the distances of AB, AC and BC and if they are all equal then Triangle ABC is an equilateral triangle :)

Answer 2

use distance formula
$\sqrt{(x2 - x1) { + }^{2}(y2 - y1) {}^{2} }$
and prove that all sides are equal