In the third year of mathematics, the following propositions are judged to be true or false

It's very clear that you're right, or you're either wrong or wrong.

Believe in yourself.

Three points determine a circle; Three points on the same straight line cannot determine a circle. So wrong.

The diameter of the bisector chord is perpendicular to the chord, and the two arcs to which the chord is bisected; This string can't be the diameter, wrong.

A quadrilateral with equal diagonals is a rectangle; Squares, isosceles trapezoids are quadrilateral and diagonally equal, not rectangular, wrong.

If the figure obtained by connecting the midpoints of the four sides of the trapezoid sequentially is a diamond, then the trapezoid is an isosceles trapezoid.

This should be right, it can't be wrong, why is it wrong???

In trapezoids, in addition to isosceles trapezoids, where the point quadrilateral is not a diamond, this proposition is true.

The last one is right, and the answer is wrong

It is possible to connect the diamond diagonal, then one diagonal is parallel to the upper and lower bottom of the trapezoid, and the other is perpendicular to the upper and lower bottom, and the two sides of the lower edge of the diamond are equal to the lower bottom, then the two triangles at the bottom corner of the trapezoid are congruent.

So it's isosceles trapezoidal.

Don't be superstitious about answers, sometimes be confident!

The answer is right, the landlord is obviously looking for troubles, rest and sleep.

Obviously, the answer is right, and if this sentence is said in reverse, the first three are clearly wrong.

In other words, I think the fourth one is right, and the landlord's proof is fine.

In the 17 questions of exercise 1, pay attention to the difference between absolute values and parentheses, and the correct answer is, the original formula = 6-(-4)-5=6+4-5=5;

In the 11 questions of practice question 2, the final calculation is wrong, and the correct result is 2;

12 questions, the writing format of the circle part is wrong, add a negative number, it should be written as + (-6) or directly written as -6;

The results of questions 17 and 18 should be negative, with a negative sign missing;

19 questions, the final result is negative or the parentheses should be removed;

There are 20 questions, and the final result score is not simplified.

It's no problem to help you look at the first one.,As for the second one, I haven't had time to look at the pretending core.,But it shouldn't be a big problem.,Master the method of arithmetic.,The result is not very important.,It's fine dust and orange heart points during the exam.,Brother Hall digs.。

The math papers in junior high school are all simple calculations, and the calculation problems are not too difficult, as long as you are serious, you can do it right.

Very good, the foundation is good, only 17 questions in exercise 1 are wrong, and the result should be 5

It's math. Mathematics. Who knows, help to see if it's right or wrong.

Question 21 on the first sheet, and question 2 on the second sheet.

The first question is the distance of the last specific place a, there is no problem in calculating, and the answer is correct.

But there is a problem in the second question, the second question, the question has been running for a long time, not running for a long time, and the back and forth has been consuming fuel, this correct calculation method should be to add the absolute value of all the routes taken, calculate the total distance run, and then multiply by the fuel consumed per kilometer.

19 Answer: The smallest positive integer c is 1, the maximum negative integer d is -1, m is less than d is negative, that is, -3, a+b is 0, and the answer should be -4

If a=b, then a=b

True propositions, inverse propositions are false propositions.

The co-angles of equal angles are equal.

True propositions, inverse propositions are true propositions.

If |a|=|b|, then a=b

False proposition, if a=1, b=-1, then |a|=|b|, but A is not equal to B

If a=b, then a = b is an inverse proposition: if a = b, then a = b, this inverse proposition is false. Counter-example: (-2) = (2), but -2≠2

Equal coangles of equal angles Inverse proposition: If the coangles of two angles are equal, then the two angles themselves are equal. This inverse proposition is a true proposition.

If |a|=|b|, then a=b inverse proposition: if a=b, then |a|=|b|This is a true proposition.

1. If a = b, then a = b, false, a can also be equal to -b

2. The co-angles are equal, true.

3. If a=b, then |a|=|b|True. The original proposition is false.

1 Inverse proposition If a = b then a=b the inverse proposition is a false proposition counterexample a =b =4 a=2 b = -a=-2

2 Inverse proposition If the co-angles of the two angles are equal, then the two angles are equitangular and the inverse proposition is true.

3 Inverse proposition If a=b then |a|=|b|The inverse proposition is a true proposition.

(1) If a=b, then a=b is wrong.

2) If the co-angles are equal, the two angles are equal. Right.

3) If a=b, then iai=ibi pairs.

1 pair Two congruent triangles can form an infinite number of figures, of course they can form axisymmetric figures2 False Two congruent triangles can form a central symmetry.

3 pairs Two triangles can form an infinite number of medium figures, and of course they can form axisymmetric figures.4 False Two congruent triangles can form a central symmetry.

5 pairs Rational numbers include integers and what is commonly called fractions, and of course rational numbers can be integers 6 pairs There are thousands of possibilities when you turn on the TV, and of course you can broadcast a football match 7 pairs If two imperfect triangles are similar isosceles triangles, they can form an axisymmetric figure.

8 False Similar isosceles triangles, stacked on top of each other are axisymmetric figures.

It's a bit of a twist, according to your teacher, "As long as you find one or more that can't be composed, it's wrong." "When your teacher says "no", he means "counterexamples", understand? Not literally, no. On the contrary, "as long as there is no counterexample, it is right".

Ah, it's a bit wordy, it's a logical problem, think about it, you can solve it by thinking about it normally, you don't have to apply every sentence of the teacher, it's not good to wrap yourself in.

1 pair, you all say it is composed, of course it can be symmetrical back to back.

2 wrong, 3 wrong. 4 false and 5 pairs, rational numbers are finite cyclic numbers, which can be integers.

6 wrong, 7 wrong, 8 wrong.

Right. Right. Wrong. The topic is said to be enclosed by a plane, not composed of a plane.

A false: I didn't say what the column was.

B True C False The sides are rectangular.

a.The upper and lower sides of the cylinder are the same size. (

b.A cylinder can be seen as a rectangle that rotates around a straight line on one side. (c.

The edged sides are triangular. (

d.Three-dimensional figures are all surrounded by flat figures. (

C is wrong, the pyramid is the triangle.

A, B is right, C and D are wrong.

Upstairs, are the balls made of flat surfaces?!!

A is wrong, I don't say what the cylinder is, B is right, C is wrong, and there is a quadrangular prism, D is right.

Because: 6 (-4) should be 6 (-4).

24-5[11]=4 should be -24-5 11=4

79-≠4 should be -79≠4