The number of diagonals in a polygon of n sides is

If the diagonals of a parallelogram bisect each other at right angles, then it will be a

For which of the following quadrilaterals, diagonals are perpendicular to each other?

The maximum number of obtuse angles that a quadrilateral can have, is

Which of the following is a regular quadrilateral?

The sides of a pentagon are produced in order. Which of the following is the sum of its exterior angles?

Which of the following is the sum of an exterior angle and its adjacent interior angle?

The sum of the measures of all the three angles of a triangle is

The angle sum of a convex polygon with number of sides n is

The measures of two angles of a quadrilateral are 110° and 100°. The remaining two angles are equal. The measure of each of the remaining two angles is

_______ is a regular quadrilateral.

If one diagonal of a rectangle is 8 cm long, length of the other diagonal is _______

All angles of rectangle are equal and are ________ angles.

A rhombus is a quadrilateral with _________ of equal length.

A square has sides of equal length and angles of equal measure, so it is a ________ polygon.

If the sum of all the exterior angles of a quadrilateral is 360° then what is the sum of all the exterior angles of an octagon?

What do we call a trapezium having its nonparallel sides equal?

Find the measure of each interior angle of a regular polygon with 12 sides.

If sum of all interior angles of a regular polygon is 18 right angles. Then, find the number of sides of the polygon.

If ABCDEF is a regular hexagon, then determine each angle of ΔAFC?

Find the perimeter of the parallelogram BCDE.

In the following figure, ABeD is a parallelogram. Find measures of x, y and z.

Take four congruent cardboard copies of any quadrilateral ABCD, with angles as shown in figure (i). Arrange the copies as shown in the figure, where ㄥ1, ㄥ2, ㄥ3 and ㄥ4 meet at a point in figure (ii).

What can you say about the sum of the angles ㄥ1, ㄥ2, ㄥ3and ㄥ4?

In the adjoining figure, find x + y + z + w.

In a quadrilateral ABCD, DO and CO are the bisectors of \(\angle\)D and \(\angle\)C respectively. Prove that \(\angle\)COD = \(\frac { 1 }{ 2 } \)[\(\angle\)A + \(\angle\)B].

Given here are some figures.

Classify each of them on the basis of the following.
(a) Simple curve
(b) Simple closed curve
(c) Polygon
(d) Convex polygon
(e) Concave polygon

Complete the following crossword puzzle using the given directions for Across [from left to right} and Down [from top to bottom).

Across:
(1) The points where, the sides of a polygon meet are called _________
(2) A polygon made by six sides is called a __________
(3) The side joining two vertices is called a ____________
(4) 'A four sided polygon is called a ____________
(5) A five sided polygon is called a  _________
Down:
(6) A parallelogram having all of its four sides equal is called a ____________
(7) A simple closed figure made of only line segments is called a __________
(8) The line segment joining the opposite sides of a polygon (except triangle) is called a ___________ of the polygon.