Mathematics problem solving in the sixth grade of primary school

1, what is the formula of semicircle circumference?

Semicircular circumference = ∏ r+2r;

2. In a rectangular flower bed 8 meters long and 6 meters wide, the largest flower bed was built. Peony flowers are planted in the annular flower bed, and jasmine flowers are planted outside the annular flower bed. What is the planting area of these two kinds of flowers?

Peony flower: (6÷2)? ×3. 14=28.26m？ ;

Jasmine: 8× 6-28.26 = 48-28.26 =19.74m? .

3. The area of a circle is half of a semicircle, and the circumference of the circle is 18.84 cm. What is the circumference of a semicircle?

Circle radius =18.84 ÷ 3.14 ÷ 2 = 3cm;

Semicircular area =(3? ×3. 14)×2=56.52cm？ ;

The square of the radius of the semicircle is 56.52 ÷ 3.14 =18; Radius = 3 √ 2 cm;

Semicircular circumference =3√2∏+6√2 (cm)

Summary of Small Class Mathematics Teaching in Kindergarten

People's Education Press, the fourth grade, Volume II, Basic Mathematics Training, Chapter V Triangle Exercise 15 (1) Answer

A summary of primary school mathematics lecture activities

How to learn the function in high school mathematics well, and what to do if you don't know it?

He normal university fractional line

The design of activity suggestions in preschool children's mathematics teaching activities refers to

About the history of postgraduate entrance examination

A 9-year-old boy's IQ is as high as 146, which is the highest in China. How are prodigies trained?

Is the college entrance examination difficult in Hebei this year?

The fifth grade mathematics volume 2, the application of circle 15 is urgent! ! ! ! ! ! ! ! !