What is the area of a equilateral triangle with a side of 12?
The formula for the Area of an equilateral triangle with side s is
For an equilateral triangle, the sides are equal and the angles are equal. So each angle is 60 degrees. If we are to drop a vertical line from the vertex angle we divide the opposite side in two equal parts. The vertex angle is also equally divided into two. Thus, we form a 30°-60°-90° triangle.
The height , h, of the right triangle in terms of the sides (s) of the equilateral triangle is
This height is also the height of the equilateral triangle whose base is s.
Generally the Area of any triangle is,
plugging in the values,