write the formulas on triangles chapter
class 9
maths
Cbsc
Answers
Answer:
Six elements of triangle Three sides and three angles
Pythagoras Theorem H2=AS2+OS2
H=HypotenuseAS=Adjacent SideOS=Opposite Side
Equilateral Triangles All sides are equal
Isosceles Triangle Two sides are equal
Step-by-step explanation:
In geometry, various shapes and structures are used for the study. Many polygons are also there. A triangle is defined as a basic polygon with three edges and three vertices. It is a very basic shape in geometry. The length of the sides, as well as all three angles, will have different values. Triangles are also divided into different types based on the measurement of its sides and angles. In this topic, we will discuss various triangles with triangle formula and suitable examples. Let us begin learning!!
What is the triangle?
As we saw that triangle is a closed polygon with minimum numbers of sides i.e. three. It is the easiest polygon which works as the base for other polygons with more number of sides. This also represents the smallest stable closed shape. Two very basic rules for a triangle are:
The sum total of all three angles will be 180∘
If∠A,∠B,and∠CarethreeanglesinaΔABC,then:
∠A+∠B+∠C=180∘
The sum of any two smaller sides will be always larger than the biggest side.
If the length of two smaller sides in Δ ABC are a and b and the largest side length is c, then: a+b> c
Types of Triangles
Triangles are of different types. Some of these are:
Equilateral Triangles: The Equilateral Triangles have the following properties:
Three sides with equal length
Three angles all equal to 60∘
Three lines of symmetry
Isosceles Triangles: The Isosceles Triangles have the following properties:
Only two sides of equal length
Only two equal angles
One line of symmetry
Scalene Triangles: Scalene triangles have the following properties
All sides of different equal lengths
All angles are different
No lines of symmetry
Acute triangles: Acute triangles have all acute angles i.e. angles less than90∘
Right Triangles: The Right Triangles is having one right angle i.e. equal to 90∘
Obtuse triangles: Obtuse triangles have one obtuse angle i.e. angle which is greater than 90∘