Types of quadrilaterals
There are six types of quadrilaterals and these quadrilaterals can be classified by the relationships of their sides and angles.
How to identify a parallelogram
A parallelogram is a four-sided polygon with two pairs of parallel and equal sides. The following figure is a parallelogram.
In a parallelogram, all the followings are true:
- Opposite sides are parallel (AB || DC and AD || BC)
- Opposite sides are equal (AB = DC and AD = BC )
- Opposite angles are equal (angle A = angle C and angle B = angle D)
How to identify a rectangle
A rectangle is a parallelogram with 4 right angles. The following figure is a rectangle.
In a rectangle, all the followings are true:
- Opposite sides are parallel (HG || EF and HE || GF)
- Opposite sides are equal (HG = EF and HE = GF)
- All four angles are equal to 90 degrees ( angle E = angle F = angle G = angle H = 90 degrees)
How to identify a square
A square is a rectangle with 4 equal sides.The following figure is square.
In a square, all the followings are true:
- Opposite sides are parallel (JK || IL and JI || KL)
- All four sides are equal (JI = KL = JK = IL)
- All four angles are equal to 90 degrees ( angle I = angle J = angle K = angle L = 90 degrees)
Rhombus: A rhombus is a parallelogram with 4 equal sides. The following figure is a rhombus.
In a rhombus, all the followings are true:
- Opposite sides are parallel (PO || MN and PM || ON )
- All four sides are equal (PO = ON = NM = MP )
- Opposites angles are equal ( angle M = angle O and angle N = angle P)
How to identify a trapezoid
Trapezoid: A trapezoid is a quadrilateral with only
one pair of parallel sides. There are three types of trapezoids.
Scalene trapezoid: A scalene trapezoid is a trapezoid with no equal sides.The following is a scalene trapezoid.
Right-angled trapezoid: A right-angled trapezoid is a trapezoid with two right angles. The following is a right-angle trapezoid.
Isosceles trapezoid: In an isosceles trapezoid, non-parallel sides are equal. The following is an isosceles trapezoid.
How to identify a kite
A kite is a quadrilateral with two pairs of adjacent sides that are equal. Furthermore, no opposite sides are equal.
Types of quadrilaterals quiz. Take the quick to check if you understand this lesson.