TOPIC- SHAPES&angles BY:- MRS.M.ghosh

1. Class –v maths TOPIC-SHAPES&angles BY:- MRS.M.ghosh

2. PART 1SOLID SHAPES

3. Two-dimensional Shapes (2D) • These shapes are flat and can only be drawn on paper. • They have two dimensions – length and width. • They are sometimes called plane shapes.

4. Objective:To describe properties of solid shapessuch as perpendicular and parallel lines, faces and edges

5. Three-dimensional Shapes (3D) • These shapes are solid or hollow. • They have three dimensions – length, width and height.

6. Face • Part of a shape that is flat.(Or curved) • E.g. A cube has 6 of these.

7. Edge • The line where two faces meet. • E.g. A cube has 12 of these.

8. Vertex (Vertices) • The place where three or more edges meet. • This pyramid has 4 of these.

9. Parallel • These type of lines stay the same distance apart for their whole length. They do not need to be straight or the same length.

10. Perpendicular • A line that is drawn in a right angle to another line . • In solid shapes edges could be at a right angle to one another. • Faces could also be at right angles to one another.

11. Cube • A three-dimensional shape which has 6 square faces all the same size. Some faces parallel Some edges parallel Some faces perpendicular Some edges perpendicular

12. Cuboid • A three-dimensional shape which has 6 rectangular faces. Some faces parallel Some edges parallel Some faces perpendicular Some edges perpendicular

13. Sphere • A perfectly round three-dimensional shape, like a ball. It has only one curved face. No parallel faces or edges No perpendicular faces or edges

14. Hemisphere • A three-dimensional shape that is half a sphere. No parallel faces or edges No perpendicular faces or edges

15. Cone • A three dimensional shape with a circle at its base and a pointed vertex. No parallel faces or edges No perpendicular faces or edges

16. Cylinder • A three-dimensional shape with circular ends of equal size. Some faces parallel Some edges parallel Some faces perpendicular No edges perpendicular

17. PART 2PLANE SHAPES

18. Polygons Two-dimensional shapes that have sides made from straight lines. • E.g. triangles squares hexagons

19. Quadrilaterals • Any two-dimensional shapes with four straight sides. • E.g. square rhombus rectangle trapezium kite

20. Rectangle • A four sided two-dimensional shape with two pairs of parallel sides that meet at right angles.

21. Kite • A two-dimensional shape with two shorter sides of equal length and two longer sides of equal length.

22. Rhombus • A two-dimensional four sided shape with opposite sides that are parallel and all the sides are the same length.

23. Trapezium • A two-dimensional shape with four sides.One pair of sides is parallel with one side longer than the other.

24. Pentagon • A two-dimensional shape with five straight sides and five angles.

25. Hexagon • A two-dimensional shape with 6 straight sides and 6 angles.

26. Octagon • A two-dimensional shape with 8 straight sides and 8 angles.

27. Circle • A round flat two-dimensional shape.

28. Square • Two dimensional shape with 4 sides of the same length and 4 90° angles.

29. Triangle • Two-dimensional shape with three straight sides and three angles. • Can you name 4 different kinds?

30. BASIC TERMS OF GEOMETRY

31. Line A line goes on and on in both directions. A line is drawn with an arrow on each end

32. This is called a point! When it’s at the end of a line it is called an endpoint!

33. Line Segment A line segment is a part of a line. It is drawn with two endpoints

34. Ray A ray goes on and on in one direction. It is drawn with an arrow on one end and an endpoint on the other.

35. DEFINITION • Angle – Two rays or two line segments that meet at a common end point.

36. A Arm of angle B C vertex Arm of angle Vertex of the angle :- B Arms of the angle :-- BA BC Naming of the angle :-- ABC or CBA or B

37. TYPES OF ANGLES Zero Angle Measure is 0° Acute Angle Measure is more than 0° but less than 90 °

38. 6. Reflex Angle Measure is more than 180° but less than 360 ° 5. Straight Angle Measure is 180° 7. Complete Angle Measure is 360°

39. Fractions for turns. • 90° = ¼ turn • 180° = ½ turn • 270° = ¾ turn • 360° =1

40. Use of Protractor for constructing an angle

41. What do we use to measure an angle? A protractor Here is a standard protractor like you use in the classroom.

42. When we use a protractor, we need to line it up correctly. You need to make sure the protractor is lined up correctly. Is this ready to measure the angle?

43. Were you right......................it wasn’t Look for the upside down ‘T’ in the middle of the straight line on your protractor. This needs to be exactly on the vertex of your angle.

44. We need to remember..... It doesn’t matter which way round the angle is, you ALWAYS need to line the upside down ‘T’ to the vertex of the angle.

45. Now you are ready. Read from the 0°, and follow the inner set of numbers.

46. Once you reach 30° you need to be careful!!! You then need to look at the 1° markings on the outer set of numbers.

47. What does it measure? This angle measures 35°.

48. What does it measure? This angle measures 60°.

49. What does it measure? This angle measures 110°.