As shown in the figure, the vertices of the shaded square are the midpoints of the sides of the larger square $\mathrm{EFGH}$. Semi-circles are drawn outward with half the sides of the larger square as diameters, and then semi-circles are drawn outward with the sides of the shaded square as diameters, forming 8 "crescent shapes". The total area of these 8 "crescent shapes" is 5 square centimeters. What is the area of the larger square EFGH in square centimeters?
3. Answer: 10

Analysis: As shown in the figure, connect $\mathrm{AB}$ and $\mathrm{CD}$ intersecting at 0. It is easy to obtain the area of triangle $\mathrm{ACH}$ using the Pythagorean theorem and the formula for the area of a semicircle, which means the area of triangle $\mathrm{AOC}$ is equal to the sum of the areas of the two "crescents" on $\mathrm{AH}$ and $\mathrm{HC}$. Therefore, the total area of these 8 "crescents" is equal to the area of square ACBD.

Since the total area of these 8 "crescents" is 5 square centimeters, and the area of square EFGH is twice the area of square ACBD, the area of square EFGH is 10 square centimeters.