How to Find the Length of One Side in an Equilateral Triangle

An equilateral triangle is a triangle whose sides and angles are all equal. Students ranging from middle school to college are required to solve problems involving equilateral triangles. This type of geometry also is useful in career fields such as engineering and landscaping. There are several relatively simple ways to obtain the length of one side of an equilateral triangle.

Things You'll Need

• Ruler
• Tape measure

Instructions

1. Duplicate the length of another side. For instance, if you are given the length of one leg, you can be sure that the other legs are the same length.

2. Measure the triangle with a ruler or tape measure (depending on how large it is).

3. Derive the length of a side by using the area and the height. If the area and height measurements are supplied, you can perform this formula for the length of a side:
   Base (or length of any side) = (2 x Area)/Height
   For instance, an equilateral triangle with a height of 8.66 and an area of 43.3 would have a side of 10, as evidenced by this equation:
   2 x 43.3 = 86.6; 86.6 / 8.66 = 10

References

• Wolfram Math World: Equilateral Triangle