Wilma used 25 square centimeters of construction paper to make a card in the shape of a square. She put a lace border around the card. How many centimeters of lace did Wilma use?

To find the perimeter of a 2D figure, you add up the lengths of all the sides. In this case, the figure is a square, a polygon that has all equal sides. So, you know that every side on the square is 25 cm long.

25 + 25 + 25 + 25 = 100

So, your answer is 100 cm of lace.