Is a quadrilateral with three angles at right angles a rectangle Reason

Yes, the three corners are right angles, and the sum of the inner angles of the quadrilateral is 360 degrees, so the remaining angles are also 90 degrees. A quadrilateral with four corners that are right angles is a rectangle.

Yes (in 2D cases).

In a two-dimensional case, the sum of the four interior angles of a quadrilateral is 360 degrees.

Now there are three angles that are 90 degrees (right angles), then the other fourth angle is also 90 degrees (right angles), and the four corners are right angles, and the quadrilateral is a rectangle.

Note: Not in the case of 3D.

Yes! The degree of the quadrilateral is: 360

The sum of the three corners is: 270

The rest is: 90

That is, it can only be at right angles.

Because, according to the sum theorem of the inner angles of the polygon, the sum of the internal angles of the quadrilateral is 360 degrees, 360-90*3=90

So the fourth angle is also 90 degrees, and according to the definition of a rectangle, a quadrilateral with all four corners at right angles is a rectangle.

Discussion on a case-by-case basis:

1.In 2D, yes: the three corners are right angles, and the sum of the inner angles of the quadrilateral is 360 degrees, so the remaining angles are also 90 degrees. A quadrilateral with four corners that are right angles is a rectangle.

2.In three dimensions, not necessarily.

Yes, this is defined in our textbooks, and if the position of the three angles is arbitrary, then the sum of any two angles is 180 degrees. Then there are two groups of opposites that are parallel to each other (complementary to the inner angles of the same side), and the two groups of quadrilaterals with opposite sides are parallelograms.

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.

A quadrilateral with three corners being right angles is a rectangle.

A parallelogram with an angle that is a right angle is a rectangle. A rectangle is a special type of parallelogram, and a square is a special rectangle. The rectangle gives us a coordinated, well-proportioned aesthetic.

Many famous buildings around the world, in order to achieve the best visual effect, have adopted the best rectangular design. Such as the Parthenon in Greece and so on.

A quadrilateral with at least three interior angles that are all right angles is a rectangle, and a rectangle contains a rectangle and a square. The rectangular property theorem is a geometric concept in mathematics, there is a parallelogram with right angles is a rectangle, the opposite sides of the rectangle are parallel and equal, the four corners are right angles, and the diagonal lines of the rectangle are parallel and equal to each other.

Properties of rectangles: Rectangles have all the properties of a parallelogram, the opposite sides are parallel and equal, the diagonal sides are equal, the adjacent angles are complementary, and the diagonals are bisected from each other. The four corners of the rectangle are all right angles.

The diagonal lines of the rectangle are equal. It is unstable (easily deformed). The rectangle must have one set of opposite sides parallel to the x-axis and another set of opposite sides parallel to the y-axis.

Geometric rectangles that do not meet this condition are considered general quadrilaterals in computer graphics. A flat fiber row quadrilateral 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.

When using letters to represent a quadrilateral, be sure to indicate the vertices in a clockwise or counterclockwise direction.

The common methods for determining a rectangle are as follows:

1. A parallelogram with an angle of right angles is a rectangle.

2. A parallelogram with equal diagonals is a rectangle.

3. A quadrilateral with three corners that are right angles is a rectangle.

4. Theorem: It has been proved that in the same plane, any two angles are right angles, and any group of quadrilaterals with equal sides is a rectangle.

5. Quadrilaterals with equal diagonals and bisected from each other are moment-destroying liquid shapes.

It is known that the quadrilateral ABCD contains the rise and elimination of ABCD, a= b= c=90 to verify the laughter: the quadrilateral ABCD is a rectangle.

Proof: Because a= b= c=90°

So ad bc, ab cd

So the quadrilateral ABCD is a parallelogram.

again a=90°

So the quadrilateral ABCD is a rectangle (a parallelogram with an angle of right angles is a rectangle).

Within a plane, there are three quadrilaterals with right angles that are rectangular (rectangular or square).

If it is not in the same plane, then there will be a lot of things with the shape of this quadrilateral, which may not be rectangular. The reason is that there are countless possibilities of right angles when they are not in the same plane, and there are countless kinds of three-dimensional figures that fit the three angles to be right angles, not necessarily rectangular.

For example, the three corners of the quadrilateral A d cd in the diagram below are right angles, but the quadrilateral is not a rectangle.

Yes, at least three quadrilaterals with right angles are rectangular, and rectangles are also called rectangles. So the four corners of the rectangle are all right angles and the diagonals are equal. A rectangle is a special parallelogram of Zhaoqing, and a square is a special rectangle.

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 from each other;

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

3) the diagonal of the rectangle is equal;

4) It is unstable (easy to deform).

1. A parallelogram with an angle of right angles is a rectangle.

2. A parallelogram with equal diagonals is a rectangle.

3. A quadrilateral with three corners that are right angles is a rectangle.

4) Theorem: It has been proved that in the same plane, any two angles are right angles, and any group of quadrilateral pants with equal sides is rectangular.

5) Quadrilaterals with equal diagonals and bisected from each other are rectangulars.

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

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

The common methods for determining a molded rectangle are as follows:

1. A parallelogram with an angle of right angles is a rectangle.

2. A parallelogram with equal diagonals is rectangular.

3. A quadrilateral with three corners that are right angles is a rectangle.

4. Theorem: It has been proved that in the same plane, any two angles are straight code selling angles, and any group of quadrilaterals with equal opposite sides is a rectangle.

5) Quadrilaterals with equal diagonals and bisected from each other are rectangulars.

To sum up, a quadrilateral with a right angle diagonally is not necessarily a rectangle.

The common methods for determining a rectangle are as follows:

1. A parallelogram with an angle of right angles is a rectangle.

2. A parallelogram with equal diagonals is a rectangle.

3. A quadrilateral with three corners that are right angles is a rectangle.

4. Theorem wheel rock: It has been proved that in the same plane, any two angles are right angles, and any group of quadrilaterals with equal opposite sides is a rectangle.

5) Quadrilaterals with equal diagonals and bisected from each other are rectangulars.

To sum up, a quadrilateral with a right angle diagonally is not necessarily a rectangle.