Pair of Angles
Pair of Angles: Overview
From this topic, we will learn about the relationship of degree with minute and second. We will discuss what angle they all represent. Furthermore, we will be able to convert one unit or measure of an angle to the other via these relationships.
Important Questions on Pair of Angles
According to angle sum property, the sum of angles in any triangle is

Prove that the sum of all interior angles of a quadrilateral is .

Show that, there is only one perpendicular drawn to a line from the external point (point not on it).

When two lines intersects at a point as shown in the figure. Then prove that, the pair of vertically opposite angles formed by the lines are equal.

Prove that , as shown in the given triangle .


Identify whether the given statement "The whole is greater than a part" is a conjecture, axiom or theorem.

Identify whether the given statement "Things which coincide with one another are equal to one another" is a conjecture, axiom or theorem.

Identify whether the given statement "Things which are equal to the same thing are equal to one another" is a conjecture, axiom or theorem.




Find the value of in the following figure.


Find the angle which is less than its supplement.


Prove the following theorem.
The perpendicular from the centre of the circle to a chord bisects the chord.

Prove the following theorem.
If the angles subtended by the chords of a circle at the centre are equal, then the chords are equal.

Prove the following theorem.
Equal chords of a circle subtend equal angles at the centre.

Prove the following theorem.
The sum of the interior angles of a triangle is .
