A circle is placed in a square with a side length of 18 mm, as shown below. Find the area of the shaded region. Use the value 3.14 for it, and do not round your answer. Be sure to include the correct unit in your answer.

Simonne used the following steps to simplify the given expression. 12-3(-2x+4) step 1: 12+(-)+(-3)(4) step 2: 12+6x+(-12) step 3: 12+(-12)+6x step 4: 0+6x step 5: 6x what property of real numbers was used to transition from step 3 to step 4? •identity property of addition •inverse property of addition •associative property of addition •commutative property of addition