To calculate the perimeter of a trapezium (or trapezoid), you need to add up the lengths of all its four sides. Here’s how you can use a calculator to find the perimeter of a trapezium:

1. Measure the length of the top base of the trapezium.
2. Write down the length of the top base.
3. Measure the length of the bottom base of the trapezium.
4. Write down the length of the bottom base.
5. Measure the length of one of the slant sides of the trapezium.
6. Write down the length of the slant side.
7. Measure the length of the other slant side of the trapezium.
8. Write down the length of the other slant side.
9. Add up the lengths of all four sides.
10. The result is the perimeter of the trapezium.

Alternatively, you can use the following formula to calculate the perimeter of a trapezium:

Perimeter = Top Base + Bottom Base + Slant Side 1 + Slant Side 2

Here’s an example to illustrate the process:

Suppose you have a trapezium with a top base length of 8 meters, a bottom base length of 12 meters, and slant sides of 6 meters each.

To find the perimeter of this trapezium, you would follow these steps:

1. Measure the length of the top base: 8 meters.
2. Write down the length of the top base: 8 meters.
3. Measure the length of the bottom base: 12 meters.
4. Write down the length of the bottom base: 12 meters.
5. Measure the length of one of the slant sides: 6 meters.
6. Write down the length of the slant side: 6 meters.
7. Measure the length of the other slant side: 6 meters.
8. Write down the length of the other slant side: 6 meters.
9. Add up the lengths of all four sides: 8 + 12 + 6 + 6 = 32 meters.
10. The perimeter of the trapezium is 32 meters.