Lines and Angles

Short Answer Questions(SAQs)

What is the definition of a ray?

In geometry, a ray is usually taken as a half-infinite line with one of the two points and taken to be at infinity.

What are adjacent angles?

Adjacent angles are two angles that have the same vertex and a side in common.

What is an exterior angle?

The exterior angle of a triangle is defined as the angle formed between one of its sides and its adjacent extended side.

MCQs

1. A straight angle is equal to:

(a) 180°

(b) 90°

(c) 45°

(d) 360°

► (a) 180°

2. The sum of all angles at a point is:

(a) 90°

(b) 180°

(c) 270°

(d) 360°

► (d) 360°

3. An angle less than 90° is called:

(a) Right angle

(b) Obtuse angle

(c) Acute angle

(d) Reflex angle

► (c) Acute angle

4. What is the measure of each angle in an equilateral triangle?

(a) 90°

(b) 45°

(c) 120°

(d) 60°

► (d) 60°

5. Two angles that sum to 90° are called:

(a) Adjacent

(b) Complementary

(c) Supplementary

(d) Reflex

► (b) Complementary

6. Two angles are supplementary if their sum is:

(a) 180°

(b) 90°

(c) 360°

(d) 45°

► (a) 180°

7. A triangle has one angle measuring 90°. What type of triangle is it?

(a) Acute

(b) Right

(c) Obtuse

(d) Equilateral

► (b) Right

8. An angle that is greater than 90° but less than 180° is called:

(a) Acute angle

(b) Reflex angle

(c) Straight angle

(d) Obtuse angle

► (d) Obtuse angle

9. What is the angle between two perpendicular lines?

(a) 0°

(b) 180°

(c) 45°

(d) 90°

► (d) 90°

10. What is the sum of interior angles of a triangle?

(a) 180°

(b) 360°

(c) 270°

(d) 90°

► (a) 180°

11. What are vertically opposite angles?

(a) Angles that lie on the same side of a line

(b) Angles that add up to 90°

(c) Equal angles opposite each other when two lines intersect

(d) Angles that are complementary

► (c) Equal angles opposite each other when two lines intersect

12. Which of these is not a type of angle?

(a) Straight angle

(b) Reflex angle

(c) Wide angle

(d) Obtuse angle

► (c) Wide angle

13. What do you call angles that lie on the opposite sides of the transversal?

(a) Corresponding angles

(b) Alternate angles

(c) Interior angles

(d) Adjacent angles

► (b) Alternate angles

14. Which angle has the largest measure?

(a) 14 of a right angle

(b) 12 of a right angle

(c) A right angle

(d) An acute angle

► (c) A right angle

15. Which of the following is true for angles in a straight line?

(a) They are equal

(b) They are reflex

(c) They sum to 90°

(d) They sum to 180°

► (d) They sum to 180°

16. In a triangle, an exterior angle is equal to the sum of:

(a) All the interior angles

(b) Two opposite interior angles

(c) One adjacent angle

(d) Right angles only

► (b) Two opposite interior angles

17. What is the reflex angle of 110°?

(a) 70°

(b) 250°

(c) 220°

(d) 140°

► (b) 250°

18. The number of angles formed when two lines intersect is:

(a) 2

(b) 3

(c) 4

(d) 6

► (c) 4