Question

summery of quadrilaterals class 9 math​

Answer 1

Answer:

quadrilateral=A plane figure bounded by four lines segments AB,BC,CD,and AD is called quadrilateral the sum of angles of the quadrilateral is 360 degree

there are various types of quadrilateral

1) parallelogram

2) rectangle

3)square

4)rhombus

5) trapezium

6)kite

important theorems

1)the sum of all four angles of a quadrilateral is 360degree

2)A diagonal of a parallelogram divides it into two congruent triangle

3)a quadrilateral is a parallelogram if

•opposite sides are equal

•opposite angles are equal

•diagonals bisect each other

4)diagonal of a rectangle bisects each other and they are equal and vice-versa

5)diagonals of a rhombus bisect each other at right angle and they are not equal and vice-versa

6) diagonal s of a square bisect each other at right angle and they are equal and vice-versa

7)the segment joining the mid points of any two sides of a triangle is parallel to third side and equal to half of it

8)the line through the mid points one side of a triangle parallel to another side intersect the third side at it's mid point

9)the quadrilateral formed by joining the mid points of the sides of a quadrilateral taken in order is a parallelogram

10)in a quadrilateral if diagonals bisect each other then it then it forms a parallelogram