Lines and Angles - Class 7 Maths

Some important points

Line segment - A line segment is a portion of a line that has two end points

Line - A line is a straight path of points that has no beginning or end

Point - A point has not size or shape, it has just position

Angle - An angle is formed when two lines or line segments meet

Arms of an angle - The lines or line segments which forms an angle are called its arms

Vertex of an angle - The meeting point of the lines or line segments is called the vertex of an angle

Acute angle - An angle greater than 0° but less than 90° is called an acute angle

Obtuse angle - An angle greater than 90° but less than 180° is called an obtuse angle

Right angle - An angle which measures 90° is called a right angle

Straight angle - An angle which measures 180° is called a straight angle

Reflex angle - An angle which is more than 180° but less than 360° is called a reflex angle

Complete angle - A complete angle is equal to 360°

Adjacent angles - Adjacent angles have the same vertex a common arm and two non-common arms

Complementary angles - When the sum of two angles is 90°, the angles are called complementary angles and each angle is said to be complement of the other angle

Supplementary angles - When the sum of two angles is 180°, the angles are called supplementary angles and each angle is said to be supplement of the other angle