Equilateral triangleAll the angles of the triangle are the same too. They are all 60 degrees. This is because the angles of a triangle all add up to 180 degrees and if they are all equal then each one is 180/3 = 60 degrees! Area of an equilateral triangle: To compute the area of an equilateral triangle, you must find its height: To find this height, you must use the Pythagorean theorem: The sides are a and the height (h) divides the base into halves (a/2) So, by the Pythagorean theorem: h = √ a 2  (a/2) 2 = √ a 2  a 2/4 = √ 3a 2/4 = a (√ 3 )/2 Now, the area of 1/2 of the equilateral triangle = (a/2) h/2 = (a h)/4 Two of them, which equals the area of the equilateral triangle = (a h)/2 = a (a√ 3 )/4 =
