Sixth grade mathematics midterm paper

Sixth grade mathematics midterm paper

Elementary school mathematics volume 11 unit test of circular cognition
Class name student number
1、 Fill in the blanks (16 points)
1. The position of the circle is determined by (). The size of the circle depends on the length of ()
2. The PI represents the multiple relationship between () and () in the same circle. It is represented by the letter (). Two decimal places are reserved, and the approximate value is ()
3. You can draw () diameters in the same circle; if you use a compass to draw a circle with a diameter of 10 cm, the distance between the two feet of the compass should be () cm
4. Draw the largest circle in the rectangle of 6cm long and 4cm wide. The circumference of the circle is () and the area is ()
5. A ring, the diameter of the outer circle is 6 decimeters, the width of the ring is 1 decimeter, and the area of the ring is ()
6. The diameter of circle a is 8 cm, which is 40% of the diameter of circle B. the circumference of circle B is ()
7. If the radius of the big circle is equal to the diameter of the small circle, the area of the big circle is () times that of the small circle, and the circumference of the small circle is ()
8. Draw circles with a radius of 4cm in a rectangle with a length of 32cm and a width of 16cm. The maximum number of such circles can be () and the sum of the areas of these circles is ()
2、 Judgment questions. (8 points)
The circumference of a circle is π times its diameter
2. The diameter of the circle is increased by four times, and the area of the circle is also increased by four times
3. The circumference of a circle with a radius of 1 cm is 3.14 cm
4. The circumference of a circle is 12.56 cm and the area is 12.56 square cm
5. The radius of the circle increases from 6 decimeters to 9 decimeters, and the area of the circle increases by 45 square decimeters
6. The longest line segment in a circle is the diameter
7. A circle is an axisymmetric figure. It has innumerable axes of symmetry
The circumference of a half circle is half the circumference of a circle
3、 Choice (9 points)
1．3.14（ ）π
A. = B. > C. < D. not sure
2. When the perimeter is equal, the largest area is ()
A. Parallelogram B. rectangle C. square D. circle
4、 Calculate the circumference of the following circles. (8 points)
1. The diameter is 6 cm. 2. The radius is 5 decimeters
5、 Calculate the area of the following circles
1. The radius is 8 cm 2. The perimeter is 9.42 m (π = 3.14)
6、 Practical questions (8 points for the first question, 6 points for each other)
1. A wire can be enclosed into a circle with a radius of 3cm. If the wire is re enclosed into a square, what is the side length of the square?
2. Use mats to form a cylindrical grain bin with a perimeter of 18.84 meters. What is the area of this grain bin?
3. The club of a factory has a round dance floor with a circumference of 37.68 meters. Now we are going to widen it by 1 meter. How much can we increase the area of the dance floor?
4. Two connected pulleys, the diameter of the big pulley is 0.54 m, the radius of the small pulley is 0.09 m, the big pulley rotates for 5 cycles, how many cycles does the small pulley need to rotate?