Area and Perimeter of Shapes Tricks and Formulas

Pythagoras Theorem

For right triangle ABC

Right Triangle ABC

Right Triangle ABC

Right Triangle ABC

Equation

For acute triangle ABC

Acute Triangle ABC

Acute Triangle ABC

Acute Triangle ABC

Equation

For obtuse triangle ABC

Obtuse Triangle ABC

Obtuse Triangle ABC

Obtuse Triangle ABC

Equation

Area of Triangle

When lengths of the sides are given

When lengths of the sides are given

When Lengths of the Sides Are Given

When lengths of the sides are given

Equation

Equation

When lengths of the base and altitude are given

When lengths of the base and altitude are given

When Lengths of the Base and Altitude Are Given

When lengths of the base and altitude are given

Equation

When lengths of two sides and the included angle are given

When lengths of two sides and the included angle are given

When Lengths of Two Sides and the Included Angle Are Given

When lengths of two sides and the included angle are given

Equation

For Equilateral Triangle

Are of Equilateral Triangle

Equilateral Triangle

Are of Equilateral Triangle

Equation

For Isosceles Triangle

Area of Isosceles Triangle

Isosceles Triangle

Area of Isosceles Triangle

Equation

Apollos Theorem

Apollus Theorem

Apollus Theorem

Apollus Theorem

If AD is the median, then:

Equation

Angle Bisector Theorem

Angle Bisector Theorem

Angle Bisector Theorem

Angle Bisector Theorem

If AD is the angle bisector for angle A, then:

Equation

Area of Quadrilateral

For Cyclic Quadrilateral

Equation

Equation

If lengths of one diagonal and two offsets are given

If lengths of one diagonal and two offsets are given

If Lengths of One Diagonal and Two Offsets Are Given

If lengths of one diagonal and two offsets are given

Equation

If lengths of two diagonals and the included angle are given

If lengths of two diagonals and the included angle are given

If Lengths of Two Diagonals and the Included Angle Are Given

If lengths of two diagonals and the included angle are given

Equation

For Trapezium

Area of Trapezium

Trapezium

Area of Trapezium

Equation

For Parallelogram

Area of Parallelogram

Parallelogram

Area of Parallelogram

Equation

For Rhombus

Area of Rhombus

Rhombus

Area of Rhombus

Equation

The halves of diagonals and a side of a rhombus form a right angled triangle with side as the hypotenuse.

For Rectangle

Area of Rectangle

Rectangle

Area of Rectangle

Equation

Perimeter of a rectangle Equation

For Square

Area of Square

Square

Area of Square

Equation

Area of a square Equation

Area of 4 walls of a room Equation

Polygons

Number of Diagonals

Equation

The sum of all the interior angles

Equation

The sum of all the exterior angles

Equation

Area of Regular Hexagon

Area of Regular Hexagon

Regular Hexagon

Area of Regular Hexagon

Area= Equation

Circle

Area of Circle

Circle

Area of Circle

Circumference

Equation

Area

Equation

Length of Arc

Equation

Area of Sector

Equation

Or

Equation

Perimeter of Sector

Equation

Ellipse

Area of Ellipse

Ellipse

Area of Ellipse

If semi-major axis Equation and semi-minor axis Equation

Perimeter of the ellipse

Equation

Area of the ellipse

Equation