you can prove any one of these statements to prove that quadrilateral
is a rectangle:
-- Opposite sides are parallel and any one angle is a right angle.
-- Opposite sides are equal and any one angle is a right angle.
-- All four angles are right angles.
-- Adjacent angles are complementary, and one of them is a right angle.
-- Opposite sides are either equal or parallel, and area is equal to the product
of two adjacent sides.
-- Diagonals are equal.
There are 5 ways to prove a Quadrilateral is a Parallelogram. -Prove both pairs of opposite sides congruent -Prove both pairs of opposite sides parallel -Prove one pair of opposite sides both congruent and parallel -Prove both pairs of opposite angles are congruent -Prove that the diagonals bisect each other
You need to prove that there are two pairs of sides with equal lengths. Imagine a rectangle A C B D Since side AB is equal in length to side CD that is one equal pair. Likewise, AC is equal to BD and is the other equal pair. Since there are two equal parallel pairs, the angles must all be 90 degrees by rules of geometry so it is a rectangle. Note: The same thing may be used to prove a square, except a square has all sides of the same length. ================================================ If you can prove any one of these statements, then your quadrilateral is a rectangle: -- Opposite sides are parallel and any one angle is a right angle. -- Opposite sides are equal and any one angle is a right angle. -- All four angles are right angles. -- Adjacent angles are complementary, and one of them is a right angle. -- Opposite sides are either equal or parallel, and area is equal to the product of two adjacent sides. -- Diagonals are equal.
Yes, that is what is rectangle is. One can prove that all of the angles are right angles.
Use squares and try it out for yourself. Get a number of squares and make a rectangle 3 squares long by 4 squares wide. Count the squares. You should have 12 squares (or 3*4). That's the best way I know to prove the formula.
One could not. The shape could be a rectangle.
From Wikipedia: "...a rectangle is any quadrilateral with four right angles". So there isn't much to prove, that's how the rectangle is defined.
A parallelogram is a quadrilateral because it has 4 sides and all quadrilaterals have 4 sides such as a square, a rectangle, a rhombus ... etc
You cannot prove it since it is not true for a general quadrilateral.
You can't. A trapezoid is a quadrilateral because it has four sides. The definition of a quadrilateral is a shape with four sides.
The formula for the area of a rectangle is length x breadth. In order to prove this works, work out an area of a rectangle using that formula.
Which of the following is a valid reason why the quadrilateral shown below is a parallelogram?
With a protractor
prove any two adjacent triangles as congruent
There are 5 ways to prove a Quadrilateral is a Parallelogram. -Prove both pairs of opposite sides congruent -Prove both pairs of opposite sides parallel -Prove one pair of opposite sides both congruent and parallel -Prove both pairs of opposite angles are congruent -Prove that the diagonals bisect each other
In a rectangle, all the opposite sides, and angles are congruent to each other. All 4 angles of the rectangle, are right angles.
a rectangle has four right angles and opposite sides are all the same length This means that a parallelogram is not always a rectangle, but a rectangle is always a parallelogram, by definition.
You need to prove that there are two pairs of sides with equal lengths. Imagine a rectangle A C B D Since side AB is equal in length to side CD that is one equal pair. Likewise, AC is equal to BD and is the other equal pair. Since there are two equal parallel pairs, the angles must all be 90 degrees by rules of geometry so it is a rectangle. Note: The same thing may be used to prove a square, except a square has all sides of the same length. ================================================ If you can prove any one of these statements, then your quadrilateral is a rectangle: -- Opposite sides are parallel and any one angle is a right angle. -- Opposite sides are equal and any one angle is a right angle. -- All four angles are right angles. -- Adjacent angles are complementary, and one of them is a right angle. -- Opposite sides are either equal or parallel, and area is equal to the product of two adjacent sides. -- Diagonals are equal.