Important Questions: Lines and Angles - Class 7 MCQ

A common unit of measurement of angles is degrees.

An angle which exactly measures 90^o is called a right angle. 

• A zero angle is defined as an angle that measures exactly 0 degrees.
• It represents a situation where two rays or lines overlap completely, resulting in no visible angle.
• This makes it distinct from other types of angles:


• Obtuse angles are greater than 90 degrees.
• Straight angles measure exactly 180 degrees.
• Right angles measure exactly 90 degrees.
• Thus, the correct term for an angle measuring 0 degrees is a zero angle.

• It forms a straight line when drawn.
• It divides the plane into two equal halves.
• In contrast, a zero angle measures 0 degrees, a right angle measures 90 degrees, and an acute angle is less than 90 degrees.
• Straight angles are commonly seen in everyday objects, like the edges of a ruler.

A protractor is a measuring instrument, typically made of transparent plastic or glass, for measuring angles. Most protractors measure angles in degrees (°). Radian-scale protractors measure angles in radians.

An infinite number of rays can be drawn from a point. 

An angle which lies between 90^o and 180^o  is called as an obtuse angle. So, 169^o  is an obtuse angle.

Extending the arms of an angle does not affect the angle between them.

The vertex of an angle is the common point of the rays that form the arms of an angle. Here, it is O.

 are the two arms of ∠DEF.

Perpendicular segments meet at a point forming right angles.

The correct option is Option C.

If OQ is perpendicular on PR, it means it forms right angles on both the sides. 

∠QOP = ∠QOR = 180° ÷ 2 = 90°

Since parallel lines are the lines which have equal distance throughout. So they never meet because they have constant distance between them.

The distance between the parallel  lines is the same. 

There are two pairs of parallel lines as the opposite sides of a rectangle are parallel.PS || QR and PQ || RS

Complementary angles add up to 90^o . ∠PQR = 20^o ⇒  Its complementary angle is 90^o−20^o = 70^o

The supplementary angle of a given angle is what, when added to the given angle, equals 180°.

To find the supplementary angle of 120°:

180°−120°=60°

So, the supplementary angle of 120° is 60°.

Answer: 3 (60°)

Since the complementary angle of 45° is 45°, if the angle is greater than 45° its complement will be lesser than 45°.