The side length is 20 cm square, its area is () square meters?

The side length is 20 cm square, its area is () square meters?

20×20＝400（c㎡）
400c㎡＝4㎡

Is the side length of a square with an area of 20 square meters really?

Solving with equations
Let the side length of a square be X
x²=20
x=2√5

A square has an area of 20 square centimeters. What is the largest circle area in this square?

The square has an area of 20
Then its side length is √ 20 = 2 √ 5
The radius of the circle with the largest area in a square is half of the side length of the square = 2 √ 5 ÷ 2 = √ 5
So the area of this circle = π (√ 5) & sup2; = 5 π = 5 × 3.14 = 15.7 square centimeter

It is known that the radius of a circle is RCM. If the radius of the circle is increased by 2cm, how many cm ^ 2 does its area increase

The area formula of a circle is π R2. The original area is π R2, and the increased area is π (R + 2) 2 = π R2 + 4 μ R + 4 μ. The difference between the two is 4 μ (R + 1)

It's a big vase with a round bottom. The perimeter of the bottom is 6.28 meters. What's the area of the bottom

6.28÷3.14＝2
2×2×3.14＝12.56

Cut a cone with a base circumference of 12.56 cm and a height of 6 cm into two identical shapes along the base diameter, and increase the surface area______ Square centimeter

12.56 △ 3.14 × 6 △ 2 × 2, = 4 × 6, = 24 (square centimeter); answer: the surface area increases by 24 square centimeter

A cylinder with a circumference of 12.56 cm on the bottom is cut into several equal parts along the radius of the bottom to form an approximate cuboid. The surface area is increased by 20 square centimeters. What is the volume of the original cylinder?

The height of the cylinder: 20 △ 2 ^ (12.56 △ 3.14 ^) 2, = 10 △ 2, = 5 (CM); 3.14 × (12.56 △ 3.14 ^) 2 × 5, = 3.14 × 4 × 5, = 3.14 × 20, = 62.8 (CC); a: the original volume of the cylinder is 62.8 cubic cm

The length of a cylindrical granary is 12.56 meters, so how many square meters does the granary cover?

2 × 3.14 = 22 × 3.14, = 12.56 (square meters); a: This granary covers an area of 12.56 square meters

There are two round granaries of different sizes. The perimeter of the bottom surface of the small granary is 12.56 meters. Its floor area is one fourth of that of the large granary, and the floor area of the large granary is 12.56 meters

Bottom radius of small granary = 12.56 △ 2 △ 3.14 = 2m
The area of the small granary is 3.14 × 2-178; it is 12.56 square meters
The area of big granary is 12.56 △ 1 / 4 = 50.24 square meters

There are two round granaries of different sizes. The perimeter of the bottom of the small granary is 12.56 meters. Its floor area is 13 times that of the large granary. How many square meters is the floor area of the large granary?

The bottom radius of small granary: 12.56 △ 3.14 △ 2 = 2 (m), the floor area of small granary: 3.14 × 22 = 12.56 (M2), the floor area of large granary: 12.56 △ 13 = 37.68 (M2); a: the floor area of large granary is 37.68 m2