Triangles : Triangles
If A,B,C are three non Collinear points ,the figure made up by three line segments AB,BC and CA is called a triangle : If A,B,C are three non Collinear points ,the figure made up by three line segments AB,BC and CA is called a triangle A B C
The Six elements of a triangle are- : The Six elements of a triangle are- 1.Side AB
2. Side BC
3. Side AC
4.Angle ABC
5.Angle ACB
6. Angle BAC A B C
Interior & Exterior of a triangle : Interior & Exterior of a triangle A B C P Q m
Various types of triangles : Various types of triangles Equilateral triangle 6 cm 6 cm 6 cm
Isosceles triangle : Isosceles triangle 6 cm 6 cm 4 cm
Scalene triangle : Scalene triangle 5 cm 13 cm 6 cm
Acute triangle : Acute triangle 40 60 80
Right triangle : Right triangle 90
Obtuse Triangle : Obtuse Triangle 120
Perimeter of a Triangle : Perimeter of a Triangle 5cm 5cm 4cm Perimeter=5cm+5cm+4cm=14cm
Properties of Triangles : Properties of Triangles
Angle sum property of a Triangle : Angle sum property of a Triangle The sum of the angles of a triangle is 180˚. A B C B C A
Angle sum property of a Triangle : Angle sum property of a Triangle 1 2 3 4 5 Angle 4 + Angle 3 + Angle 5=180º
Angle 1 + Angle 3 + Angle 2=180º
Exterior & Interior Opposite Angles : Exterior & Interior Opposite Angles A B C D
Exterior angle property of a Triangle : Exterior angle property of a Triangle A B D C Angle A + Angle B = Angle BCD
Exterior angle property of a Triangle : Exterior angle property of a Triangle A B D C Angle A + Angle B + Angle BCA=180º
Angle BCA + Angle BCD=180º Angle A + Angle B +Angle BCA = Angle BCA+ Angle BCD
Triangle Inequality Property : Triangle Inequality Property The sum of any two sides of a triangle is greater than the third side. A B C AB+BC >AC
AB+AC>BCAC+BC>AB
Triangle Inequality Property : Triangle Inequality Property A B C AB+BC >AC
Triangle Inequality Property : Triangle Inequality Property A B C AB+AC>BC
Triangle Inequality Property : Triangle Inequality Property A B C AC+BC>AB
Pythagoras Theorem : Pythagoras Theorem In a right triangle, the square of the
longest side is equal to the sum of squares of remaining two sides. A B C ( AC) 2 = (AB) 2 + (BC) 2
Hypotenuse 2 = Perpendicular 2 + Base 2 Base Perpendicular Hypotenuse
Pythagoras Theorem : Pythagoras Theorem