Class 6 • Mathematics • Chapter 5
Understanding Elementary Shapes
Learn how to measure line segments, identify angles and understand basic geometrical shapes such as triangles, quadrilaterals and circles.
Learn the Basics
Important Concepts
Understand the basic shapes and measurements.
Measuring Line Segments
Learn how to measure the length of a line segment using a ruler.
Types of Angles
Understand right, acute, obtuse and other basic types of angles.
Right Angle
Identify a right angle and understand its measure.
Triangles
Explore triangles and their basic characteristics.
Quadrilaterals
Learn about four-sided closed figures and their properties.
Circles
Understand the basic parts and features of a circle.
Understand with Examples
Worked Examples
Right Angle
90°
Triangle
A triangle has three sides.
Circle
A circle has a centre and radius.
Measurement
Measuring a Line Segment
Place the zero mark of the ruler at one endpoint of the line segment. Read the measurement at the other endpoint carefully.
Quick Notes
Remember These Points
- • A line segment has two endpoints and a definite length.
- • A right angle measures 90°.
- • An acute angle is smaller than a right angle.
- • An obtuse angle is greater than 90° but less than 180°.
- • A triangle has three sides and three vertices.
- • A quadrilateral is a closed figure with four sides.
Practice
Practice Questions
Measure a line segment AB of 5 cm using a ruler.
Name an angle that measures 90°.
What type of angle is smaller than a right angle?
How many sides does a quadrilateral have?
Name the three sides of a triangle using suitable labels.
Identify the centre of a circle in a given figure.
Test Yourself
Revise angles, shapes and measurements, then test your understanding.