If ABC is a triangle, then it is denoted as ∆ABC, where A, B and C are the vertices of the triangle. A triangle is a two-dimensional shape, in Euclidean geometry, which is seen as three non-collinear points in a unique plane.
Properties
Each and every shape in Maths has some properties which distinguish them from each other. Let us discuss here some of the properties of triangles.
- A triangle has three sides and three angles.
- The sum of the angles of a triangle is always 180 degrees.
- The sum of the lengths of any two sides of a triangle is greater than the length of the third side. Similarly, the difference between the lengths of any two sides of a triangle is less than the length of the third side.
Types
On the basis of the length of the sides, triangles are classified into three categories:
- Scalene Triangle
- Isosceles Triangle
- Equilateral Triangle
On the basis of measurement of the angles, triangles are classified into three categories:
- Acute Angle Triangle
- Right Angle Triangle
- Obtuse Angle Triangle
Scalene Triangle
Isosceles Triangle
Equilateral Triangle
Acute Angled Triangle
Right Angled Triangle
Obtuse Angled Triangle
Perimeter of Triangle
A perimeter of a triangle is defined as the total length of the outer boundary of the triangle. Or we can say, the perimeter of the triangle is equal to the sum of all its three sides. The unit of the perimeter is the same as the unit of sides of the triangle.
If ABC is a triangle, where AB, BC, and AC are the lengths of its sides, then the perimeter of ABC is given by:
Perimeter = AB+BC+AC
Area of a Triangle
The area of a triangle is the region occupied by the triangle in 2d space. The area for different triangles varies from each other depending on their dimensions. We can calculate the area if we know the base length and the height of a triangle. It is measured in square units.
Formula:
Area of triangle = Half of Product of Base and Height
Area = 1/2 × Base × Height
And
In case, if the height of a triangle is not given, we cannot be able to use the above formula to find the area of a triangle.
Therefore, Heron’s formula is used to calculate the area of a triangle, if all the sides lengths are known.
First, we need to calculate the semi perimeter (s).
s = (a+b+c)/2, (where a,b,c are the three sides of a triangle)
Now Area is given by; A = √[s(s-a)(s-b)(s-c)]