# Class 9 Maths Worksheet for Quadrilaterals

Given below are the Class 9 Maths Worksheet for Quadrilaterals
a. Concepts questions
b. Calculation problems
c. Multiple choice questions
e. Fill in the blanks
Question 1
ABCD is a parallelogram and AP and CQ are perpendiculars from vertices A and C on diagonal BD. Show that :
(i) $\Delta APB \cong \Delta CQD$
(ii) AP = CQ

Question 2
The angles of a quadrilateral are in the ratio 3 : 5 : 7 : 9. Find the angles of the quadrilateral.
Question 3
In a quadrilateral ABCD, AO and BO are the bisectors of $\angle A \; and \; \angle B$ respectively. Prove that $\angle AOB = \frac {1}{ 2} (\angle C + \angle D)$
Question 4
In the figure, ABCD is a parallelogram. E is the mid-point of BC. DE and AB when produced meet at F. Prove that AF = 2AB

Question 5
ABCD is a square and on the side DC, an equilateral triangle is constructed. Prove that
(i) AE = BE
(ii) $\angle DAE = 15^0$

Question 6
ABCD is a rectangle in which diagonal BD bisects ∠B. Show that ABCD is a square.
Question 7
If ABCD is a trapezium in which AB || CD and AD = BC, prove that ∠A = ∠B
Question 8
In the figure, diagonal BD of parallelogram ABCD bisects ∠B. Show that it bisects ∠D also

Question 9
E and F are points on diagonal AC of a parallelogram ABCD such that AE = CF. Show that BFDE is a parallelogram.
Question 10
The two opposite angles of a parallelogram are $(3y - 10)^0$ and $(2y + 35)^0$. Find the measure of all the four angles of the parallelogram

Question 11
ABCD is a rhombus in which AC = 16 cm and BC = 10 cm. Find the length of the diagonal BD.
Question 12
Diagonals of a quadrilateral ABCD bisect each other. If ∠A = 35°, then ∠B = 145°. Is it true ? Justify your answer.
Question 13
Can $\angle 95^0 \; ,\; 70^0 \; ,\; 110^0 \; and \; 80^0$ be the angles of a quadrilateral ? Why or why not ?
Question 14
Prove that quadrilateral formed by bisectors of the angles of a parallelogram is a rectangle.

Question 15
Show that the line segments joining the mid-points of opposite sides of quadrilateral bisect each other.
Question 16
ABCD is a parallelogram in which X and Y are the mid-points of AB and CD. AY and DX are joined which intersect each other at P. BY and CX are also joined which intersect each other at Q. Show that PXQY is a parallelogram
Question 17
Show that if the diagonals of a quadrilateral bisect each other at right angles, then it is a rhombus
Question 18
If one angle of a parallelogram is a right angle, it is a rectangle. Prove.