My classmates' handwriting is good, and I think their Chinese scores are not bad either. Can't you do so many math problems together?

1, this question is really not suitable for sixth-grade students. It can be sued that the maximum radius of a semicircle is equal to √ 74/2;

2. The problem of "turning a circle into a square" ... π * d = 4a, a = π d/4 = π (m);

3. The path around the flower bed is equivalent to a ring, and the inner diameter and outer diameter are r= 10 m and r =11m respectively; Area S=π( 1 1? - 10? )=2 1π(m？ );

4. The original planned grain output 1200-300=900 (tons), with an overproduction rate of 300/900 =1/3 = 33.3%;

5. The sum of interest on the principal due for three years =20000*( 1+3.69%)? ;

* * * earned interest P=20000[( 1+3.69%)? -1]≈2296.70 (yuan);

6. The radius of semicircle r = √ (2 *14.13/π) ≈ 3cm, assuming that the peripheral border is square, the side length is 6 cm and the shadow width is 3cm;

The diameter of the small circle is d = 2 √ (19.625/π) ≈ 2 * 2.5 = 5.0 cm ... This "small circle" is too big to hold;

7. The area of the outer square minus the area of each quarter circle of the four corners is the area of the concave quadrangle, and the area of the inscribed circle minus the area of the concave quadrangle is equal to the shadow area;

∴ Shadow area =π( 10/2)? -[ 10? -π( 10/2)? ]=50π- 100 cm？ ;

8. Equation method: If the weight of glycogen in package B is x grams and that in package A is 4g, then (4x-130)/(x+130) = 7/5;

When solving the equation, X=325, so 4x= 1300 (g);