The sum of the areas of two circles with a diameter of 10 cm is equal to that of a circle with a diameter of 20 cm______ ．

The sum of the areas of two circles with a diameter of 10 cm is equal to that of a circle with a diameter of 20 cm______ ．

The sum of the areas of two circles with a diameter of 10 cm: 3.14 × (10 △ 2) 2 × 2 = 157 (square centimeter), the area of a circle with a diameter of 20 cm: 3.14 × (20 △ 2) 2 = 314 (square centimeter), 157 square centimeter ＜ 314 square centimeter, so it is wrong that the sum of the areas of two circles with a diameter of 10 cm is equal to the area of a circle with a diameter of 20 cm