1) Find out what area the square had with sides of 15 cm.
15 * 15 = 225 cm².
2) Find out the length of the side of the square if it was increased by 3 cm, and the original length of the side of the square was 15 cm.
15 + 3 = 18 cm.
3) Find the area of the new square if the length of its sides is 18 cm.
18 * 18 = 324 cm².
4) Let’s find out what the difference was made by the area.
324 – 225 = 99 cm².
5) Find out by how many% the area of the square has increased.
225 – 100%
99 – X%.
99 * 100/225 = 44%.
Answer: the area of the square has increased by 44%.
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