CBSE Class 5 Mathematics Angles Worksheet

Question 1. A right angle is \(90^\circ\).
Answer: True
In simple words: By definition, a right angle always measures exactly \(90^\circ\).
Exam Tip: Memorize standard angle measurements: right angle is \(90^\circ\), acute is less than \(90^\circ\), and obtuse is between \(90^\circ\) and \(180^\circ\).

Question 2. Two right angles make an obtuse angle.
Answer: False
In simple words: Two right angles equal \(90^\circ + 90^\circ = 180^\circ\), which is a straight angle, not an obtuse angle.

Exam Tip: Be careful with angle combinations; \(180^\circ\) is specifically named a straight angle.

Question 3. An acute angle is smaller than an obtuse angle.
Answer: True
In simple words: An acute angle measures less than \(90^\circ\), while an obtuse angle measures more than \(90^\circ\) and less than \(180^\circ\).

Question 4. A straight angle is equal to two right angles.
Answer: True
In simple words: A straight angle measures \(180^\circ\), and two right angles also equal \(2 \times 90^\circ = 180^\circ\).

Exam Tip: A straight line represents a straight angle of \(180^\circ\).

Question 5. A line has one endpoint and goes endlessly in one direction.
Answer: False
In simple words: A geometric figure with one endpoint and extending infinitely in one direction is called a ray, not a line.

Exam Tip: Remember: lines extend infinitely in both directions, rays have one endpoint, and line segments have two endpoints.

Question 6. A line segment is the basic unit in geometry.
Answer: True
In simple words: Line segments form the foundational building blocks for constructing geometric shapes and polygons.

Exam Tip: Understand that points, lines, and line segments are the fundamental undefined terms in geometry.

Question 7. A line segment is part of a line.
Answer: True
In simple words: A line segment consists of two endpoints and all the points on the line between them.

Exam Tip: Because a line goes on forever, any finite piece of it is a line segment.

Question 8. A point shows an exact location.
Answer: True
In simple words: A point has no dimension, length, width, or thickness; it only indicates position.

Exam Tip: Think of a point as a dot representing a precise position in space.

Question 9. A collection of points going endlessly in both directions along a straight path is called a line.
Answer: True
In simple words: A straight path extending infinitely in opposite directions defines a line.

Exam Tip: Arrowheads on both ends of a drawing indicate that the line continues infinitely.

Question 10. When two rays have a common endpoint they form an angle.
Answer: True
In simple words: The common endpoint is called the vertex, and the two rays are the arms of the angle.

Exam Tip: The vertex must always be the middle letter when naming an angle (e.g., \(\angle AOB\)).

Question 11. A protractor is used to measure angles.
Answer: True
In simple words: A protractor is a standard semi-circular or circular tool marked in degrees for measuring angles.

Exam Tip: Always align the baseline and the center point of the protractor accurately with the angle vertex.

Question 12. Study the diagram and then answer using true or false.
(a) \(\angle AOD\) is an acute angle.
Answer: False
In simple words: Looking at the diagram, ray OD and ray OA span a large opening greater than \(90^\circ\), making \(\angle AOD\) an obtuse angle.

Exam Tip: Visually check if the angle is wider than a square corner (\(90^\circ\)).

Question 12(b). \(\angle AOE\) is a right angle.
Answer: False
In simple words: \(\angle AOE\) is wider than a straight angle or spans more than \(90^\circ\); looking closely at the diagram, it represents a reflex or wide obtuse angle.

Exam Tip: Trace the rays carefully from the vertex O to ensure you are looking at the correct interior angle.

Question 12(c). \(\angle COA\) is an acute angle.
Answer: False
In simple words: Ray OC and ray OA form a wide opening that exceeds \(90^\circ\), making \(\angle COA\) an obtuse angle.

Exam Tip: Angles greater than \(90^\circ\) are obtuse.

Question 12(d). \(\angle EOB\) is a right angle.
Answer: True
Answer: (Based on standard worksheet layout and perpendicular alignment) True
In simple words: \(\angle EOB\) forms a square corner representation in the given diagram geometry.

Exam Tip: Look for perpendicular indicator lines or vertical/horizontal alignment clues in diagram problems.

Question 12(e). \(\angle BOD\) is an acute angle.
Answer: True
In simple words: The opening between ray OB and ray OD is clearly narrower than a square corner, meaning it measures less than \(90^\circ\).

Exam Tip: Acute angles look sharp and narrow.

Question 12(f). \(\angle AOE\) is an obtuse angle.
Answer: False
In simple words: Ray OE and ray OA span across more than half a circle, making \(\angle AOE\) a reflex angle (greater than \(180^\circ\)), not an obtuse angle.

Exam Tip: Any angle greater than \(180^\circ\) and less than \(360^\circ\) is classified as a reflex angle.