Chapter 5: Understanding Quadrilaterals & Practical Geometry

Solution:-

If the diagonals of a quadrilateral bisect each other, it is a Parallelogram.

Solution:-

The adjacent sides of a parallelogram are 5 cm and 9 cm. Its perimeter is 28 cm.

We know that, perimeter of Parallelogram = 2 × (sum of lengths of adjacent sides)

= 2 × (5 + 9)

= 2 × 14

= 28 cm

Solution:-

A nonagon has 9 sides.

Solution:-

Diagonals of a rectangle are equal.

Solution:-

A polygon having 10 sides is known as Decagon.

Solution:-

A rectangle whose adjacent sides are equal becomes a Square.

Solution:-

If one diagonal of a rectangle is 6 cm long, length of the other diagonal is 6cm.

Because, diagonals of a rectangle are equal.

Solution:-

Adjacent angles of a parallelogram are supplementary.

Solution:-

If only one diagonal of a quadrilateral bisects the other, then the quadrilateral is known as kite.

Solution:-

In trapezium ABCD with AB||CD, if ∠A = 100^o, then ∠D =80^o.

We know that, in trapezium adjacent angles of non – parallel sides are supplementary.

∠A + ∠D = 180^o

100^o + ∠D = 180^o

∠D = 180^o – 100^o

∠D = 80^o