## PERIMETER AND AREA - ESSENTIAL POINTS

• Perimeter is the distance around a closed figure whereas area is the part of plane occupied by the closed figure.
• Area is the measure of the part of plane or region enclosed by it.
• Basic formulas for areas and perimeters.
• Perimeter of a square = 4 × side
• Perimeter of a rectangle = 2 × (length + breadth)
• Area of a square = side × side
• Area of a rectangle = length × breadth
• Area of a parallelogram = base × height
• Area of a triangle = 1/2 (area of the parallelogram generated from it) = ½ × base x height
• Area of equilateral triangle = × side
• Area of a circle = πr2, where r is the radius of the circle.
• The distance around a circular region is known as its circumference.
• The ratio of circumference and diameter of a circle is a constant is denoted by π (pi).
• Circumference of a circle = πd, where d is the diameter of a circle and π = 22/7 = 3.14 (approximately).
• Based on the conversion of units for lengths, studied earlier, the units of areas can also be converted:
• 1 cm2 = 100 mm2
• 1 m2 = 10000 cm2
• 1 hectare = 10000 m2