Area and Perimeter of Shapes Tricks and Formulas

Pythagoras Theorem

For right triangle ABC

For acute triangle ABC

For obtuse triangle ABC

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 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 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

Apollos Theorem

If AD is the median, then:

Angle Bisector Theorem

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

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 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

For Rhombus

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

For Rectangle

Perimeter of a rectangle

For Square

Area of a square

Area of 4 walls of a room

Area=

Or