Xiao Hua splits a circle into several parts along the radius and forms an approximate rectangle. The circumference of the rectangle is 41.4cm. What is the area of the rectangle?

Xiao Hua splits a circle into several parts along the radius and forms an approximate rectangle. The circumference of the rectangle is 41.4cm. What is the area of the rectangle?

Let the radius of a circle be r, then its circumference is 2 π R. from the meaning of the title, we can get: & nbsp; & nbsp; 2 π R + 2R = 41.4, (2 π + 2) r = 41.4, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; r = 41.4 △ 2 × 3.14 + 2, & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; r = 41.4 △ 8.28; R = 5; s = π R2, = 3.14 × 52, = 3.14 × 25, = 78.5 (square centimeter); a: the area of this rectangle is 78.5 square centimeter

Put a circle into an approximate rectangle. Given that the circumference of the rectangle is 41.4cm, what is the area of the circle

Radius of a circle
41.4 △ (1 + 3.14) △ 2 = 5cm
Area: 5 × 5 × 3.14 = 78.5 square centimeter

Divide a circle into several parts evenly and make it into an approximate rectangle. The circumference of the rectangle is 41.4cm. What is the area of the circle in square centimeter?

Radius = 41.4 ﹣ 2 ﹣ 3.14 + 1 = 5cm
Area of circle = 3.14 × 5 & # 178; = 78.5 square centimeter