﻿ Area - Facts and Formulae
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# Area - Facts & Formulae

## I.FACTS ON TRIANGLES:

1. Sum of the angles of a triangle is 180 degrees.
2. Sum of any two sides of a triangle is greater than the third side.
3. Pythagoras theorem:
In a right angle triangle,
(Hypotenuse)^2 = (base)^2 + (Height)^2
4. The line joining the midpoint of a side of a triangle to the opposite vertex is called the MEDIAN
5. The point where the three medians of a triangle meet is called CENTROID.
Centroid divides each of the medians in the ratio 2:1.
6. In an isosceles triangle, the altitude from the vertex bi-sects the base
7. The median of a triangle divides it into two triangles of the same area.
8. Area of a triangle formed by joining the midpoints of the sides of a given triangle is one-fourth of the area of the given triangle.

## II.FACTS ON QUADRILATERALS:

1. The diagonals of a parallelogram bisects each other .
2. Each diagonal of a parallelogram divides it into two triangles of the same area
3. The diagonals of a rectangle are equal and bisect each other.
4. The diagonals of a square are equal and bisect each other at right angles.
5. The diagonals of a rhombus are unequal and bisect each other at right angles.
6. A parallelogram and a rectangle on the same base and between the same parallels are equal in area.
7. Of all the parallelograms of a given sides , the parallelogram which is a rectangle has the greatest area.