Find 15 fill in the blank questions about the knowledge of circle parts to have answers

1. (Cactus thorns) pointed.

2. (nib) pointed.

3. (The moon) is crooked.

4. (Path) crooked.

5. (Watermelon) round.

6. (lotus leaf) round.

1. Perpendicular diameter theorem and reasoning.

Perpendicular diameter theorem:(

If one of the diameters of a circle is perpendicular to a string, then the diameter bisects the chord and the arc to which the string is opposed.

Corollary: (1),

The diameter of the bisector string (not the diameter) is perpendicular to the string, and the two arcs opposite the chord are bisected.

The perpendicular bisector of the string passes through the center of the circle and bisects the arc to which the string is opposed.

The diameter of one arc to which the bisect string is directed bisects the chord perpendicularly and bisects the other arc to which the chord is opposite.

In an identical or equal circle, the arcs sandwiched by two parallel chords are equal.

2. The relationship between the central angle, arc, chord and chord center distance.

Theorem: (In the same circle, the arcs of the opposite angles are equal, the opposite strings are equal, and the chord centroid distance of the opposite strings is also equal, and the corollary: (

In the same circle or equal circle, if one set of quantities is equal in the central distance of two circles, two arcs, two strings, or two chords, then the rest of the groups of quantities corresponding to them are equal.

3. The nature of the tangent of the circle (1), the property theorem (

The tangent of the circle is perpendicular to the radius of the tangent point.

2), inference 1 (

A straight line that passes through the tangent perpendicular to the tangent must pass through the center of the circle.

3), inference 2 (

A straight line perpendicular to this radius through the tangent point is a tangent of a circle.

4. Concepts related to the inner and outer tangent circles of triangles (polygons).

A circle tangent to all three sides of a triangle.

Called the inscribed circle of the triangle, (

The center of a triangle inscribed circle.

It is called the heart of the triangle, and this triangle is called the round (.)

Inscribed triangle.

A circle tangent to all sides of a polygon.

It is called the inscribed circle of the polygon, and this polygon is called the round (inscribed polygon.

The circle that intersects all the corners of the polygon is called the circumscribed circle of the polygon, and this polygon is called the circumscribed polygon of the circle.

There is no such thing as an inscribed circle.

The diameters in the figure are: ab; Non-diameter strings are: EF, DC;

In the arc with the call of a as the endpoint in the circle, the optimal arc balance pin has arc ace and acd, adc, adf;

Inferior arcs are: arc AF, AC, AD, and chain roll AE.

Arcs larger than semi-circles are called superior arcs, and arcs smaller than semi-circles are called inferior arcs. ）

Fill-in-the-blank questions. 1. The distance from the front point of each stool on the circle to the center of the circle is equal to the distance from the center of the circle to the point where the radius is equal

1) Diagonal intersection point.

1. Fill-in-the-blank questions, 1The circumference of a circle is always more than (3 times) the diameter, and this multiple is fixed, which we call (pi).

2.When drawing a circle, the distance between the feet of the compass is circle (radius), draw a circle with a circumference of centimeters, and the distance between the feet of the compass is ( ) centimeters, 3The radius of the circle is 2 cm, its diameter is (4) cm, its circumference is ( ) cm, and the area is ( ) square centimeters, if the radius of the circle is expanded to twice the original size, the circumference of the enlarged circle is ( ) cm and the area is ( ) square centimeters.

4.Cut the largest circle in a square with a side length of 6 centimeters, and the area of the circle is ( ) square centimeters.

5.If the wire is enclosed into a circle, the radius of the circle is (2) decimeters, and the area is ( ) square decimeters, 6A ring, the radius of the outer circle is 8 decimeters, the radius of the inner circle is 2 decimeters, and the area of this ring is ( ) square decimeters, 7If the radius of a circle increases by 1 cm, its diameter increases by (2) cm, and its circumference increases by (8).The radius of a semicircle is 6 decimeters, its circumference is ( ) decimeters, 9, the circle is ( axis ) figure, it has ( countless ) axes of symmetry, two, multiple-choice, 1A circle and a square with equal circumference, the area of the circle (a) The area of the square, a, greater than b and less than c are equal to.

2.The diameter of the minor circle is equal to the radius of the great circle, and the area of the minor circle is equal to the area of the large circle (a).

a, a quarter b an eighth c a sixteenth.

3.The distance traveled by the wheel in one revolution is to find the wheel (b).

a, diameter b perimeter c area.

4.The central angle of the circle is 40°, and the sector area is the area of the circle in which it is located (b).

a, one-sixth b, one-ninth, c-eighth.

5.The radius of the circle is enlarged by four times, the circumference and area are enlarged by (c) times, a, 4 and 8 b 4 and 4 c 4 and 16, respectively

3. True/False questions, (correct or false in parentheses).

1.The area of a full circle is larger than that of a semicircle, (right).

2.The longer the circumference of the circle, the larger the area of the circle, (right).

3.The line segment that passes through the center of the circle is called the diameter, (wrong).

4.The radius is 2 centimeters and the circumference and area of a circle are equal, (wrong).

5.Within the same circle, the diameter is the longest line segment, (right).

If the above questions are answered well, neatness + speed + accuracy = 20-50 reward!

The following is a simple addition, and all pairs will add 5-10 points.

r= Find the diameter.

Diameter d = 2r = 7

c= find the diameter, and the diameter d=c

r=8 cm d=12 dm Find the perimeter and area, 1) Circumference c = cm, s = square centimeter.

2) Circumference c = decimeter, s = square decimeter.

d = 8 m r = 5 cm Find the perimeter and area, 1) Perimeter c = m, s = square meters.

2) Circumference c = cm, s = square centimeter.

Fainting These little minions are so hard.

I don't want to think about it.

The landlord asked the wrong place.

I don't help with homework here.

It's great to have money, look at you and you can't do any of this, blow !!

1b2a

3b4b5c1.The area of a full circle is larger than that of a semicircle, (right).

2.The longer the circumference of the circle, the larger the area of the circle

3.The line segment that passes through the center of the circle is called the diameter, (wrong).

4.The radius is 2 centimeters and the circumference and area of a circle are equal, (right)5Within the same circle, the diameter is the longest line segment, (wrong).

1.Center Radius Radius.

2.Pi.

7.Perimeter radius.

8.πr9.The length of the segment area.

10.Isosceles triangle Rectangle Equilateral triangle Square Circle.

11.No, do it yourself.

Centimeter. Centimeter.

m square meters.

m square meters.

Square metre. take

If you haven't done this kind of question for a long time, you may make mistakes, please forgive me. 】

1 Intersect (15).

2 There is something wrong with the first empty question, and it can't be done.

Second space: r>6

1.If the two circles have a distance of 2, one of them has a radius of 3, and the other has a radius r>1, then the position of the two circles may be: intersect or contain.

2.If the centricity of two circles is 3, and the radius of one of the circles is 3, (the condition is missing here?) When two circles are contained, the radius r of the other circle should satisfy r>6