lines and angleskkkkkkkkkkkkkkkkkkkkkkkkkkk.pptx

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1. A PRESENTATION ON LINES AND ANGLES BY ARINJAY SUAR CLASS-IX, TULIP

2. LINES LINE - A straight path extending in both direction with no end points. LINE SEGMENTS – A part of a line that includes two points , called endpoints and all the points between them. RAY – Apart of a line , with one endpoint that continues without end in one direction. INTERSECTING LINES – When two or more lines cut each other in such a way that there is a common point is known as intersecting line. NON-INTERSECTING/ PARALLEL LINES - When two or more lines run concurrently but do not cross each other at any point , are known as non-intersecting lines. They are also known as parallel lines. PERPENDICULAR LINES – A straight line that makes the right angle (90 ) with the other line.

3. ANGLES An angle is formed when two lines/edges/rays intersect or meet at a common end point. The common point of their contact (i.e. a corner) is called the vertex of an angle Types of Angles- Acute angles :- Measuring from 0 degree to 90 degree. vertex Arm

4. TYPES OF ANGLES 2. OBTUSE ANGLES- Measuring from 90 degree to 180 degree 3. RIGHT ANGLES- 90 Degree 4. STRAIGHT ANGLE – 180 Degree

5. TYPES OF ANGLES 5. COMPLETE ANGLES- 360 degree 6. REFLEX ANGLES – 180 Degree to 360 degree 7. OPPOSITE ANGLES 8. COMPLENTARY ANGLES 9. SUPPLEMENTARY ANGLES

6. USAGE OF LINES AND ANGLES IN DAILY LIFE REAL LIFE EXAMPLES OF LINE – Pencil, chess board, stick, scale, edge of any surface like table, bed etc. USAGE – In the classrooms, straight lines are drawn on the floor and the entrance. Zebra crossing on the roadside. In construction, graphic design lines are used in different ways. They are also represented in railway tracks. REAL LIFE EXAMPLES OF ANGLES- Cloth hangers, scissors, arrowhead, cycle spokes, blades of a fan, hands of a clock, etc. USAGE – Position, direction, precision and optimization are some ways in which people use angles in their daily life. Carpenters use them to measure precisely to build doors, chairs, tables, etc. Athletes use them to gauge the distance of a throw and to enhance their performance in sports.

7. When angles share a vertex and fill the space around a point, they add to 360 degree. When two lines cross, opposite angles are equal. When a line intersects parallel lines, alternate angles are equal. When a line crosses parallel lines, corresponding angles are equal. Two parallel lines never meet each other. The distance between two parallel line is always equal. An angle is formed when two rays intersect each other in the same plane. When two parallel lines are intersected by a transversal, then the pair of interior angles on the same side of it are supplementary If a transversal intersects two lines such that a pair of interior angles on the same side of transversal are supplementary, then the two lines are parallel to each other. INTERESTING FACTS ABOUT LINES AND ANGLES

8. THANK YOU