Unit 1 Examination Questions (1)

1. Fill in the blank: 30 points.

1. When drawing a circle, the distance between the compasses is 4cm, so the diameter of the circle is () cm, the circumference is () cm, and the area is () square cm.

2. The circumference of a circle is more than () times its diameter. This multiple is a fixed number. We call it (), which is usually represented by the letter (). Is () decimal, take two decimal places is ().

3. A circle is a () figure with () symmetry axis. A semicircle has a () axis of symmetry.

4. Divide a circle into several parts evenly, and you can make a figure similar to a parallelogram. The smaller the division, the larger the parallelogram of the graph (). The base of a parallelogram is equal to () of the circumference, which is higher than (). Because the area of parallelogram is equal to (), and the area of circle is equal to (), which is represented by letters.

5. Draw a circle with the length of 18.84DM, the radius of the circle is () DM, and the area inside the circle is () square decimeter.

6. Cut out the largest circle on a rectangular cardboard with a length of 8 cm and a width of 5 cm. The area of this circle is () square decimeter.

7. There are () line segments with both ends on the circle, of which () is the longest. The diameter and radius of a circle are ().

8. The center of the circle determines the circle (), and () determines the circle ().

9. If the radius of a circle is doubled, its circumference is doubled and its area is doubled.

10, the circle with the same center is called () circle, and the circle with different center positions and the same radius is called () circle.

1 1. The quotient of the circumference and diameter of a circle is called (), which is represented by the letter ().

12. In an equicircle, all diameters are (), all radii are (), and diameters are radius ().

13. When the diameter of a circle is expanded by three times, its circumference is expanded by () times and its area is expanded by () times.

14. A rectangle has a () axis of symmetry. A square has () axis of symmetry, an isosceles triangle has () axis of symmetry, and a circle has () axis of symmetry.

2. Judgment: 10.

1, the diameter is twice the radius, and the radius is 1/2 of the diameter. ( )

2. The line segment with both ends on the circle and passing through the center of the circle is the diameter. ( )

3. The symmetry axis of a circle is the straight line where the diameter lies. ( )

The circumference of a circle is 3. 14 times the diameter. ( )

5. Two radii are one diameter. ( )

6. A circle with a radius of 2 cm has the same area and circumference. ( )

7. The circumference of a semicircle is the circumference of a circle divided by 2.

8. Divide a circle into n small sectors on average. When the value of n is larger and larger, each small sector is closer to the triangle, and its height is closer to the radius. ( )

9. The diameter is always greater than the radius. ( )

10. Three equal-length iron wires are used to form a rectangle, a square and a circle respectively, and the circle has the largest area. ( )

Third, multiple choice questions. Fill in the serial number of the correct answer in (). 5 points

1, the areas of two circles are not equal, because ().

A, pi is different; B, the position of the center of the circle is different; C, the radius is different.

2. The perimeters of the two circles are equal, so the area of the two circles is ().

A, not sure B, must be unequal C, must be equal

3, the diameter of the two circles is 4 cm, and the perimeters of the two circles are different ()

A, 4cm b, 12.56cm c, uncertain.

4, the symmetry axis in the following figure is the least ()

A, circle b, square c, rectangle d, isosceles triangle e, parallelogram

5. The () passing through the center of the circle with both ends on the circle is called the diameter of the circle.

A, ray b, line segment c, straight line

Fourth, the operation questions. 6 points

1. Draw a circle with a diameter of 5cm. The radius, diameter and center of a circle are represented by letters.

2. Draw the symmetry axis of the picture below.

5. Calculate the area and perimeter of the shaded part in the figure below. 20 points

The side length of a square is 5cm, the diameter is 8cm, and the diameter is12cm.

Sixth, the application problem. 29 points

1, a semicircular flower bed, its area is 56.52 square meters, what is the perimeter of this flower bed? 6 points

2. Pave a 4m-wide circular road around the circular grassland with a diameter of 18m. What is the area of this circular road? 6 points

3. A round desktop with a diameter of 80 cm. Now, put a glass of the same size on the desktop and find the area of this desktop glass. If the price of glass is RMB 100 per square meter, how much is this glass? 6 points

4. Circular grassland with an area of 2,826 square meters. What is the diameter of this meadow? 6 points

5. Find the area of a circular pond with a diameter of 30 meters. 5 points

Seven, additional questions: fill in the blanks.

1. The quotient of the circumference and diameter of a circle is called (), which is represented by the letter ().

2. In an equal circle, all diameters are (), all radii are (), and diameters are radii ().

3. When the diameter of a circle is tripled, its circumference is multiplied by () times and its area is multiplied by () times.

4. The rectangle has a () axis of symmetry. A square has () axis of symmetry, an isosceles triangle has () axis of symmetry, and a circle has () axis of symmetry.