Triangle 

A triangle is a plane figure bounded by three straight lines. A triangle has three sides and three angles, and each one of them is called an element of the triangle.

Triangle

Here, PQR is a triangle, its three sides are line segments PQ, QR and RP; ∠PQR, ∠QRP and ∠RPQ are its three angles.

The point at which any two sides meet is called a vertex. Thus, a triangle has three vertices. The vertices of the triangle PQR are P, Q and R.

The side opposite to a vertex is called a base.

The above figure of a triangle PQR, QR is the base when the vertex is P. 


Exterior opposite angles:

If a side QR of a triangle PQR is produced to S then the ∠PRS is called the exterior angle at R.

Exterior and Interior Opposite Angles

Interior opposite angles:

The two opposite angles, that is ∠PQR and ∠QPR are called interior opposite angles.


Perimeter:

The sum of the three sides of a triangle is called the perimeter of the triangle. 

Perimeter

The perimeter of the triangle PQR is (PQ + QR + RP)





9th Grade Math

From Triangle to HOME PAGE




Didn't find what you were looking for? Or want to know more information about Math Only Math. Use this Google Search to find what you need.



Share this page: What’s this?

Recent Articles

  1. Dividing 3-Digit by 1-Digit Number | Long Division |Worksheet Answer

    Apr 24, 24 03:46 PM

    Dividing 3-Digit by 1-Digit Number
    Dividing 3-Digit by 1-Digit Numbers are discussed here step-by-step. How to divide 3-digit numbers by single-digit numbers? Let us follow the examples to learn to divide 3-digit number by one-digit nu…

    Read More

  2. Symmetrical Shapes | One, Two, Three, Four & Many-line Symmetry

    Apr 24, 24 03:45 PM

    Symmetrical Figures
    Symmetrical shapes are discussed here in this topic. Any object or shape which can be cut in two equal halves in such a way that both the parts are exactly the same is called symmetrical. The line whi…

    Read More

  3. Mental Math on Geometrical Shapes | Geometry Worksheets| Answer

    Apr 24, 24 03:35 PM

    In mental math on geometrical shapes we will solve different type of problems on simple closed curves, polygons, basic geometrical concepts, perpendicular lines, parallel lines, circle, terms relates…

    Read More

  4. Circle Math | Terms Related to the Circle | Symbol of Circle O | Math

    Apr 24, 24 02:57 PM

    Circle using a Compass
    In circle math the terms related to the circle are discussed here. A circle is such a closed curve whose every point is equidistant from a fixed point called its centre. The symbol of circle is O. We…

    Read More

  5. Fundamental Geometrical Concepts | Point | Line | Properties of Lines

    Apr 24, 24 12:38 PM

    Point P
    The fundamental geometrical concepts depend on three basic concepts — point, line and plane. The terms cannot be precisely defined. However, the meanings of these terms are explained through examples.

    Read More