A quadrilateral with all four corners at right angles must be a parallelogram, right?

A quadrilateral with all four corners at right angles is a parallelogram, also called a rectangle (or rectangle), and the square has four equal sides in addition to the four equal corners.

A rectangle, a mathematical term, is a parallelogram with a corner that is at a right angle called a rectangle. It is also defined as a parallelogram with all four corners at right angles, and at the same time, a square is a special rectangle that is also a diamond shape.

Definition of rectangle length and width.

1. The long side of the rectangle is called long, and the short side is called wide.

2. The one in the same direction as the horizontal plane is called long, and vice versa is called wide. The length and width of a rectangle are relative, and it cannot be absolutely said that "length is longer than width", but it is customary to say that the long one is long and the short one is wide.

That's right, a quadrilateral with all four corners at right angles must be a rectangle, and a rectangle belongs to a parallelogram.

Hello landlord! It's a drop. That's right, thank you. Wish.

。It's a must...

Or is it a rectangle?

The rectangle is definitely a parallelogram.

It is wrong for a quadrilateral to have 4 right angles. There are many types of quadrilaterals, such as squares, rectangles, parallelograms.

Rhomboids, trapezoids, etc., and many irregular quadruple deformations. In these quadrilaterals, only squares, rectangles have four right angles. So the statement that quadrilaterals have 4 right angles is one-sided and incorrect.

Characteristics of the four noisy rock edges:

1) The quadrilateral shape has four sides and four corners.

2) The sum of the inner and outer angles of the quadrilateral is 360 degrees.

3) Quadrilaterals are unstable.

According to the characteristics of the parallelogram, the parallelogram is unstable and easy to deform. The deformability of the parallelogram has been widely used in daily life, such as telescopic doors, lifting frames, and electric sliding doors at the entrance of residential areas.

telescopic hangers, etc.

Mistake. Not all quads have four right angles.

The analysis process is as follows:

A closed plane figure or three-dimensional figure enclosed by four line segments that are not on the same straight line and do not cross each other end to end is called a quadrilateral, which is composed of a convex quadrilateral and a concave quadrilateral.

There are only four corners of the rectangle and square in the quadrilateral, so it is a mistake to say that the quadrilateral has four right angles.

One corner is a right angle, and the other three corners are also right angles. So this parallelogram is a rectangle.

The two diagonal lines are equal; The two diagonals are bisected with each other; The two sets of opposite sides are parallel to each other; The two sets of opposite sides are equal; All four corners are right angles; There are 2 axes of symmetry (4 for squares); It is unstable (easily deformed); The square of the diagonal length of the rectangle is the sum of the squares of the two sides; The quadrilateral obtained by sequentially connecting the midpoints of each side of the rectangle is a diamond.

The opposite sides of a parallelogram are parallel to each other, and the condition for a rectangle to be satisfied is that there are two sides parallel to each other, and there is a figure with an angle at right angles, so a parallelogram with an angle at right angles is a rectangle.

Rectangles --- parallelograms are parallel and equal to the opposite sides.

The diagonal is equal, and the two adjacent angles complement each other, that is, the two adjacent angles add up to 180° – one angle is a right angle, i.e. equal to 90°

Then its diagonal is equal to it, which is also equal to 90°

The two adjacent angles are equal to 180°-90°=90°, that is, if the four corners of the parallelogram are all 90°, then it is rectangular.

Rectangle!

Among them, the rectangle is divided into a rectangle and a square!

Each quadrilateral has four right angles that are wrong, only the rectangle has four vertical angles, and the other quadrilaterals are not four right angles. A quadrilateral is a closed plane or three-dimensional figure enclosed by four line segments that are not connected to each other in the same straight line, and there is no limit to the angle.

Quadrilaterals can be divided into convex quadrilaterals and concave quadrilaterals. The scum quadrilateral obtained by sequentially connecting the midpoint on any quadrilateral is called a midpoint quadrilateral, and the midpoint quadrilateral is a parallelogram.

The midpoint quadrilateral of the rhombus is rectangular, the midpoint quadrilateral of the rectangle is rhombus, and the isosceles trapezoid.

The midpoint quadrilateral is a diamond, and the midpoint quadrilateral of a square is a square.

There is a band of disturbances, where the inner angles are right-angled, and the parallelogram with equal diagonals is rectangular. A rectangle is a special type of parallelogram, and a square is a special rectangle. A rectangle is also called a rectangle.

Area: s=ab (note: a is long, b is wide).

Circumference: c=2(a+b) (note: a is long, b is wide).

A parallelogram is a closed figure composed of two sets of parallel line segments in the same two-dimensional plane. Parallelograms are generally named with the name of the figure plus four vertices. Note: When using letters to represent quadrilaterals, be sure to indicate each vertex in a clockwise or counterclockwise direction.

Parallelogram Properties:

1. If a quadrilateral is a parallelogram, then the two sets of opposite sides of the quadrilateral are equal.

2. If a quadrilateral is a parallelogram, then the two sets of diagonal diagonals of this quadrilateral are equal.

3. If a quadrilateral is a parallelogram, then the adjacent angles of this quadrilateral complement each other.

4. The parallel height sandwiched between two parallel lines is equal.

Rectangle properties: Since the rectangle is a special parallelogram, it contains the properties of the parallelogram; The properties of the rectangle are roughly summarized as follows:

1. The rectangle has all the properties of a parallelogram: the opposite sides are parallel and equal, the opposite angles are equal, the adjacent angles are complementary, and the diagonals are bisected by each other;

2. The four corners of the rectangle are all right angles;

3. The diagonal lines of the rectangle are equal;

4. It is unstable (easy to deform).

Wrong. A closed plane figure or three-dimensional figure enclosed by four line segments that are not on the same straight line is called a quadrilateral, which is composed of a convex quadrilateral and a concave quadrilateral. The quadrilateral obtained by sequentially connecting the midpoints on any quadrilateral is called a midpoint quadrilateral, and the midpoint quadrilateral is a parallelogram.

The four vertices are in the same plane, the opposite edges do not intersect and make a straight line on one side, and the other edges are on the same side.

Parallelograms (including: normal parallelograms, rectangles, diamonds, squares).

Trapezoidal (including: ordinary trapezoidal, right-angled trapezoid, isosceles trapezoid).

The sum of the inner and outer angles of a convex quadrilateral is 360 degrees.

The four vertices of a concave quadrilateral are in the same plane, the opposite sides do not intersect and make a straight line on one side, and some of the other sides are on the opposite side.

The quadrilateral obtained by connecting the midpoints of each side of the quadrilateral in turn is called a midpoint quadrilateral. No matter how the shape of the original quadrilateral changes, the shape of the midpoint quadrilateral is always parallelogram. The shape of the midpoint quadrilateral depends on the diagonal of the original quadrilateral.

If the diagonal of the original quadrilateral is perpendicular, the midpoint quadrilateral is rectangular; If the diagonals of the original quadrilateral are equal, then the midpoint quadrilateral is a diamond; If the diagonals of the original quadrilateral are both perpendicular and equal, then the midpoint quadrilateral is a square.