The diagonal AC divides the rectangle into two equal right angle triangles. Parallelogram trapezoid trapezium triangle rhombus kite regular polygon circle and ellipse. The area A of a rectangle is the product of its length l and width w.
Area ABCD Area ABC Area ADC.
The diagonal AC divides the rectangle into two equal right angle triangles. Thus the formula for the area A of a rectangle whose length and width are l and w respectively is the product l w. A more detailed explanation in text and video of each area formula. Area of rectangle Length x Width A L W where A is the area L is the length W is the width or breadth.