A triangle is geometric figure which has three sides and adjacent to each side is an angle so the triangle has three sides and three angels. There are different types of triangles either a right angle triangle, isosceles triangle etc. An equilateral triangle is a triangle which has all three sides equal to each other. So if we consider that out of three sides of the triangle one is the base (the horizontal one) and the second one is perpendicular (the vertical one) and the third one is the hypotenuse (the inclined one), and then if we further assume that we have two of such equilateral triangles placed one above the other than it will take the form of a square. Normally for an tetrahedron the formula for calculating the area is base into height i.e. Perpendicular in this case so we will calculate the area of this imaginary tetrahedron by multiplying base with perpendicular but this would be the are for the imagined square i.e. Two triangles for one triangle we will divide it by two and hence the formula will be half of the multiple of base and perpendicular. The units of this are will be square meter.