Leia cuts congruent triangular patches with a area of 45 square centimeters from a rectangular piece of fabric that is 18 centimeters

Let's assume that the rectangular piece is a square.

So first, we need to find the total area of the fabric.

Area = 18 * 18

Area = 324 cm^2

The area of a triangular patch is 45 cm^2.

So, there are

No. of patches = 324 / 45

No. of patches = 7.2

So, there are 7 triangular patches made from the whole fabric.