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Right Triangle Formula

Explore more about the right triangle with solved examples.

Right Triangle Formula

A triangle is a closed figure with 3 sides, 3 angles and 3 vertices and for right triangles formulas, the properties have to be more specific.  If any one of the angles of a triangle is a right angle measuring 90°, the triangle is called a right angled triangle or simply, a right triangle.  

A right triangle formula would help you solve variety calculations related to the perimeter area, etc of the right triangle.

What are the Right Triangles Formulas?

A right-angled triangle is one which has one of its interior angles measuring 90 degrees.  Right angled triangle formulas are used to calculate the perimeter, area, height, etc of a right triangle using its three sides.

Pythagoras theorem: (Hypotenuse)² =(Altitude)² + (Base)²

Area = 1//2 × base altitude

Perimeter = Hypotenuse + Base + Altitude.

Right Angled Triangle Formula:

Different formulas associated with the right triangle are:

  • Pythagoras theorem formula definition shows relations among the three sides of a right triangle.  The square of the hypotenuse is equal to the sum of squares of the other two sides.

(Hypotenuse)² =(perpendicular)² +(Base)²

  • Area of a right triangle formula is given as 

Area =1/2 × Base height = ½ × b h

Where height, h is equal to the length of the perpendicular side of the triangle.

  • The perimeter of a right triangle formula is given as 

Perimeter = a + b + c 

Where a, b and c are the three sides of the triangle.

Example:

Question: The length of the base and perpendicular of a right-angled triangle is 6 in and 3 in respectively. Find the length of its hypotenuse, the perimeter of the triangle and area of the triangle.

Solution:

Length of base =6 in, length of perpendicular = 8 in

1. Using Pythagoras’ theorem,

(Hypotenuse = (Base + (Perpendicular

(Hypotenuse =  + = 100

Hypotenuse = √100 = 10 in

2. Using the perimeter of a right triangle formula,

Perimeter = 6+8+10= 24in

3. Using the area of triangle formula 

Area=  (1/2) b ×h

             (1/2) ×6 × 8 = 24in².

Important formulas:

Rectangle formulaDiagonal of rectangle formulaIsosceles triangles formula
Equilateral triangle formulaDouble angle formulasEquilateral triangle formulas
Right angle formulaHalf angle formulaSides of triangle formula
Isosceles triangle perimeter formulaSum of exterior angles formulaClock angle formula
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Frequently asked questions

Get answers to the most common queries related to the right triangle formula.

What is a right triangle?

Answer: A right angle is an angle that is exactly equal to 90 degrees.  The hypotenuse is the longest side o...Read full

Is it possible to have two right angles in a triangle?

Answer: No, it is impossible for a triangle to have two right angles .  We know that a triangle consists of ...Read full