NCERT Chapter Summary: Basic Geometrical Ideas

NCERT Chapter Summary: Basic Geometrical Ideas

This chapter introduces basic concepts and terms related to geometry.

A line is made up of an infinite number of points, and a plane is made up of an infinite number of lines.

Different types of angles: acute angles (less than 90 degrees), obtuse angles (greater than 90 degrees but less than 180 degrees), right angles (exactly 90 degrees), and straight angles (exactly 180 degrees).

Triangles: A triangle is a closed figure formed by three line segments.

Types of triangles: based on their sides (scalene, isosceles, and equilateral) and angles (acute, obtuse, and right).

Quadrilaterals: A quadrilateral is a closed figure formed by four line segments.

Different types of quadrilaterals: squares, rectangles, parallelograms, rhombuses, and trapeziums.