Example 4: The areas of two similar triangles are 45 cm 2 and 80 cm 2. By using this website, you agree to our Cookie Policy. Thus, by applying Pythagoras Theorem, we can calculate the height to be [(sqrt3)/2]*a. The perimeter of an equilateral triangle is 60 m. The area is (a)10√3 m 2 (b) 15√3 m 2 (c)20√3 m 2 (d) 100√3 m 2 Thinking Process (i) First, determine the side of an equilateral by usingformula, perimeter=3x. In an equilateral triangle, all of the sides are congruent (they are the same length). So, the area of the triangle is: Because the sum of the areas is 75 cm 2, you get . By observation, each contributes only 1 side to the overall perimeter, thus we can simply multiply 36(5) = … Let us know if you have any other suggestions! Find the perimeter of each triangle. The perimeter of an equilateral triangle is simply the sum of its three sides which are equal in length and is represented as P=3*s or Perimeter=3*Side. An equilateral triangle has three equal angles of 60 degrees each. If you call the triangles Δ 1 and Δ 2, then . Free Equilateral Triangle Area & Perimeter Calculator - Calculate area, perimeter of an equilateral triangle step-by-step This website uses cookies to ensure you get the best experience. Let a be the length of the sides, A - the area of the triangle, p the perimeter, R - the radius of the circumscribed circle, r - the radius of the inscribed circle, h - the altitude (height) from any side.. Thus, if an equilateral triangle has a side length of #2#, the perimeter is #2+2+2# because all of its sides are #2#. The ratios of the sides of a 30-60-90 triangle are 1 : √3 : 2, where the sides are: Short side = 1 The perimeter is 17.7 when the length of a side is 5.29. According to Theorem 60, this also means that the scale factor of these two similar triangles is 3 : 4. What is the constant of proportionality The perimeter of an equilateral triangle can be calculated with this formula: Perimeter = a + a + a = 3a. The first, and easier one, is recognizing how much of the perimeter the equilateral triangles take up—since there are 40 triangles in total, there must be 40 – 4 = 36 of these triangles. Reduced equations for equilateral, right and isosceles are below. The sum of their perimeters is 35 cm. Equilateral triangle formulas. The perimeter of any polygon is the sum of its side lengths. The side is an upright or sloping surface of a structure or object that is not the top or bottom and generally not the front or back. Scalene Triangle Equations These equations apply to any type of triangle. Below are the 5 different choices of calculations you can make with this equilateral triangle calculator. The perpendicular bisector creates two equal but mirror-image right triangles with angles of 30, 60, and 90 degrees. 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