One vertex of an equilateral triangle is 2,−1 whose area is 123 .The perpendicular distance from the vertex 2,−1 to opposite side is
2
12
22
32
In an equilateral triangle, if h is the height of the triangle, then its area is h23.
Here,
h23=123h2=12h=12
Therefore, the distance from one vertex to the opposite side is 12