Monday, April 15, 2013

Finding the perimeter measure of an equalateral triangle,

How to find the perimeter of an equalateral triangle. Watch the video for two practice problems, one easy, the second problem is more challenging. 

Problem 1. What is the perimeter measure of an equilateral triangle that has a side measure of 4 units?
Step 1. We will use the formula 3s (s= one side length)
Step 2.  3 x 4 = 12 units

Problem 2. This one is a little more challenging.
What is the perimeter measure of an equilateral triangle with a height of 6 units?
Step 1. The height measure cuts the equilateral triangle into two 30-60-90 triangles.
The altitude becomes the long leg so let’s work backwards.

Step 2. The short leg will be  



Step 3. Now we have half the distance of one side. The whole length equals



 


Step 4. Apply the perimeter formula of 3xside
 

For more information please see Perimter Formulas