All questions of Geometry for Year 4 Exam

The boundary of a circle is circumference

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Understanding Tangrams
Tangrams are a classic puzzle consisting of geometric shapes that can be rearranged to form various figures. The set includes seven specific shapes that can create a wide array of designs, making it a fascinating tool for learning about geometry and spatial relationships.
Components of Tangrams
The seven shapes that make up a tangram set are:
- Two Large Triangles
- One Medium Triangle
- Two Small Triangles
- One Square
- One Parallelogram
Explanation of the Seven Shapes
1. Two Large Triangles: These are the largest pieces and can be used in various configurations to form larger shapes.
2. One Medium Triangle: This piece complements the large triangles and adds versatility to the designs.
3. Two Small Triangles: These smaller shapes are perfect for filling gaps and adding detail to the overall figure.
4. One Square: The square acts as a base or a component in many tangram designs, providing stability to the overall configuration.
5. One Parallelogram: This shape introduces a unique angle and can create dynamic designs when combined with other pieces.
Conclusion
In conclusion, the correct answer is option 'B', which signifies that a tangram is made up of seven distinct geometric shapes. This variety allows for immense creativity and problem-solving opportunities, making tangrams an excellent educational tool for children.

Understanding the Concept of a Plane
A plane is a fundamental concept in geometry. To clarify why option 'B' is the correct answer, let’s explore the definition and characteristics of a plane.
Definition of a Plane
- A plane is defined as a flat surface.
- It extends indefinitely in all directions, meaning it has no boundaries or edges.
Characteristics of a Plane
- Flat Surface: Unlike three-dimensional objects, a plane does not have height or depth; it is purely two-dimensional.
- Indefinite Extension: A plane continues infinitely, which means it does not end at any point, unlike a line segment or a bounded shape.
- No Curvature: A plane is perfectly flat and does not curve; this distinguishes it from curved surfaces, such as spheres or cylinders.
Why Other Options are Incorrect
- Option A (A three-dimensional object): This describes objects like cubes or spheres, which have length, width, and height. A plane is strictly two-dimensional.
- Option C (A point in space): A point is a location with no dimensions, which is different from a plane that has width and length.
- Option D (A curved surface): This option describes surfaces that are not flat, such as the surface of a ball. A plane must remain flat.
In summary, option 'B' accurately captures the essence of a plane in geometric terms, highlighting its flatness and infinite nature. Understanding this concept is crucial as it forms the basis for more complex geometric principles.

Understanding Lines and Line Segments
Lines and line segments are fundamental concepts in geometry, and it’s important to distinguish between them.
Definition of a Line
- A line is an infinitely long straight path that extends in both directions without any endpoints.
- It continues indefinitely, which means there is no fixed length associated with a line.
Definition of a Line Segment
- A line segment, on the other hand, is a part of a line that has two distinct endpoints.
- This means it has a specific length that can be measured, as it only stretches between those two points.
Key Differences
- Length: A line has no length limitation, while a line segment has a definite length determined by the distance between its endpoints.
- Endpoints: A line has no endpoints, whereas a line segment has exactly two endpoints, marking where it begins and ends.
Why Option B is Correct
- The correct answer states that "A line is infinitely long, whereas a line segment has a fixed length." This accurately reflects the fundamental difference in their definitions.
- Recognizing this distinction is crucial for understanding more complex geometric concepts later on.
In summary, while both lines and line segments are straight paths, the infinite nature of a line and the fixed length of a line segment set them apart.

Understanding Shapes That Can Be Drawn Without Crossing
When considering shapes that can be drawn without crossing themselves, it's important to analyze the characteristics of each option provided.
Option A: A Simple Closed Figure
- A simple closed figure is defined as a shape that is completely enclosed and does not intersect itself at any point.
- Examples include circles, squares, and triangles.
- These shapes can be traced continuously without lifting the pencil or crossing any lines.
Option B: An Open Shape
- An open shape, such as a line or curve that does not return to its starting point, can be drawn without crossing itself.
- However, the question specifically asks for a shape that is closed, which excludes this option.
Option C: A Polygon with Intersecting Sides
- A polygon with intersecting sides is a shape where the lines cross each other.
- This results in a figure that cannot be traced without crossing over some lines, making it an incorrect choice.
Option D: A Line Segment
- A line segment is a straight path connecting two points and does not form a closed shape.
- While it can be drawn without crossing itself, it does not meet the criteria of being a closed figure.
Conclusion
- The only shape that meets all criteria of being a simple closed figure and can be drawn without crossing is Option A.
- Thus, a simple closed figure is the correct answer as it allows for continuous tracing without any intersections.

Understanding Line Types
Lines can be classified into different categories based on their orientation and relationship to each other. Here’s a breakdown of the types mentioned in the question:
1. Parallel Lines
- These lines never meet or intersect.
- They maintain a constant distance from each other.
- Example: Train tracks.
2. Intersecting Lines
- These lines cross each other at any angle.
- The angle at which they intersect can vary.
- Example: The intersection of streets.
3. Perpendicular Lines
- Perpendicular lines are a special type of intersecting lines.
- They intersect at a right angle, which measures 90 degrees.
- Example: The edges of a square or rectangle.
4. Skew Lines
- Skew lines are lines that do not intersect and are not parallel.
- They exist in different planes.
- Example: The edges of a box that do not meet.
Conclusion
The correct answer to the question is option 'C', Perpendicular lines, because they are specifically defined by their right angle intersection. Understanding the characteristics of these lines helps in geometry, making it easier to identify and work with different shapes and angles.