How to Find the Perimeter of a Trapezoid

Step-by-Step Guide

1. 1

   Step 1: Set up the formula for perimeter of a trapezoid.

   The formula is P=T+B+L+R{\displaystyle P=T+B+L+R}, where P{\displaystyle P} equals the perimeter of the trapezoid, and the variables T{\displaystyle T} equals the length of the top base of the trapezoid, B{\displaystyle B} equals the length of the bottom base, L{\displaystyle L} equals the length of the left side, and R{\displaystyle R} equals the length of the right side., If you do not know the length of all four sides of the trapezoid, you cannot use this formula.
   
   For example, if you have a trapezoid with a top base of 2 cm, a bottom base of 3 cm, and two side lengths of 1 cm, your formula will look like this:
   P=2+3+1+1{\displaystyle P=2+3+1+1} , This will give you the perimeter of your trapezoid.
   
   For example:
   P=2+3+1+1{\displaystyle P=2+3+1+1}P=7{\displaystyle P=7}So, the perimeter of the trapezoid is 7 cm.
2. 2

   Step 2: Plug the side lengths into the formula.

3. 3

   Step 3: Add the side lengths together.

Detailed Guide

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