Triangle Tutorial

Triangle Definition:

A triangle has three corners or vertices and three sides or edges which are straight line segments.

Equilateral Triangle Definition:

Equilateral triangle is a triangle that has equal length on all three sides.

SAS Triangle Definition:

If two sides and the included angles of two triangles are correspondingly equal, the two triangles are congruent. This is called SAS Triangle.

Triangle Formula :

Area of Triangle = l * b/2 Perimeter of Triangle = a + b + c Area of Equilateral Triangle = (Sqrt(3) / 4) * l² Area of SAS Triangle = ½ * l * b * SinC

where

l = length, b = breadth a, b, c = sides of triangle

Equilateral Triangle Image/Diagram

SAS Triangle Image/Diagram

Triangle Example :

Case 1:

Find the area of a triangle from the given length 3 and breadth 4.

Step 1:

Find the area. Area = l * b/2 = 3 * 4/2 = 12/2 = 6.

Case 2:

Find the perimeter of a triangle from the given side 1, 2, 3.

Step 1:

Find the perimeter. Perimeter = a + b + c = 1 + 2 + 3 = 6.

Case 3:

Find the area of a equilateral triangle from the given length 3.

Step 1:

Find the area. Area = (Sqrt(3) / 4) * l² = (1.73 / 4) * 3² = 0.43 * 9 = 3.87.

Case 4:

Find the area of a SAS triangle from the given length 3 and breadth 4 and angle 28 degree.

Step 1:

Find the area. Area = ½ * l * b * SinC = 0.5 * 3 * 4 * Sin(28) = 6 * 0.27 = 1.62. The above example will clearly illustrates how to calculate the Area, Perimeter of a Triangle, Equilateral Triangle, SAS Triangle manually.

Triangle Tutorial