Quadrilateral

A quadrilateral is a four sided polygon. A quadrilateral has four sides, four vertices and four interior angles. The sum of the interior angles is 360°. Diagram 1 shows examples of quadrilaterals.

The different types of quadrilaterals are rectangle, square, parallelogram, rhombus and trapezium.

Rectangle

• A rectangle has four equal interior angles of 90°. 
• The opposite sides of a rectangle are parallel to each other and has equal length.  
• The two diagonals of a rectangle bisect each other. This means the diagonals meet at the same midpoint. This midpoint divides each diagonal into two equal parts. 

Square

• All four sides of a square have equal length.  
• A square has four equal interior angles of 90°. 
• The opposite sides of a square are parallel to each other.
• The two diagonals of a square bisect each other. 
• The diagonals intersect at 90°.

Parallelogram

• The opposite sides of a parallelogram are parallel to each other and has equal length.  
• The two diagonals of a parallelogram bisect each other. 
• The opposite angles of a parallelogram have the same value.
• The sum of adjacent angles of a parallelogram is 180°.

In Diagram 4, ∠A = ∠C and ∠B = ∠D. 

Also, ∠A + ∠B = ∠A + ∠D =  ∠B + ∠C = ∠C + ∠D = 180°.  

Rhombus

• All four sides of a rhombus have equal length.  
• The opposite sides of a rhombus are parallel to each other and has equal length.  
• The opposite angles of a rhombus are equal.
• The diagonals of a rhombus bisect each other and intersect at 90°.
• The sum of adjacent angles of a rhombus is 180°.

Trapezium

• A trapezium has a pair of parallel opposite sides. The other two sides are not parallel.
• The diagonals of a trapezium bisect each other.
• The sum of adjacent angles of a trapezium is 180°.

Kite

• A kite has two pairs of equal length sides. The equal sides are adjacent.
• One of the two diagonals bisect the other diagonal. 

References: https://quizizz.com/admin/quiz/5fc92b88af7501001b86305c/properties-of-rectangles-rhombuses-and-squares