Angles 1
- 1. Angles : All you should know By the end of the lesson you will be able to : • Use appropriate mathematical vocabulary related to angles. • Recognise and calculate angles between parallel lines. • Use angle properties of triangles and quadrilaterals. 1
- 2. What do you call an angle whose measure is less than 90o? Acute is 135o? Obtuse 360º? A complete turn is180º? Straight angle Which of the following angles is a reflex angle? a) 178º b) 200º c) 270º d) 320º e) 360º b) c) and d) reflex angle : 2
- 3. What is the complementary angle of α= 26o ? An angle of 64o. complementary angles: supplementary angles: 3
- 4. What is the name for angles 1 and 2? Vertically opposite. 1 2 Vertically opposite angles are equal. 4
- 5. Two vertically opposite angles measure 2x and 80o. How many degrees are there in x? o 40 1 2x 80º 2 Two supplementary angles measure (5x30) and (x+90) degrees. What is the value of x ? 20o 5
- 6. Classify the angles below according to their position. α and β are adjacent α β What can be said about the values of angles α and β? α + β = 180o Adjacent angles add up to 180o. 6
- 7. a // b c a 1 2 4 3 b 5 6 8 7 Name all interior angles. 3,4, 5 and 6 Name all exterior angles. 1, 2, 7, 8. 7
- 8. a // b c a 1 2 4 3 b 5 6 8 7 Name all pairs of alternate interior angles. 4 and 6, 5 and 3 Name all pairs of alternate exterior angles. 1 and 7, 2 and 8. Alternate angles between parallel lines are............. 8
- 9. a // b c a 1 2 4 3 b 5 6 8 7 Name all pairs of corresponding angles. 1and 5, 2 and 6, 4 and 8, 3 and 7. Corresponding angles between parallel lines are ............. 9
- 10. a // b c a 1 2 4 3 b 5 6 8 7 Name all pairs of cointerior (or conjugate interior) angles. 5 and 4, 3 and 6 Name all pairs of coexterior (or conjugate exterior) angles. 1 and 8, 2 and 7. Conjugate angles between parallel lines...................... 10
- 11. a Which line is the transversal? p r 1 140o p // a Find the measure of: 2 3 140o o r 140 40o 11
- 12. a // b What is the value of x ? (x+80)o 20 a b (5x)o c 12
- 13. Find the size of o 18 13
- 14. Triangles clasification by sides ...................... ...................... ...................... 14
- 15. by angles .................... .................... .................... 15
- 16. B o Find the size of 2x+ 10 60o 3x + 40o C x 20o A The sum of the interior angles of any triangle is........ 16
- 17. B 48o α+θ= θα o T α = 52 P α is an exterior angle, because is adjacent to an interior angle of the triangle PBT. 17
- 18. Quadrilaterals Quad Family Tree.notebook 18
- 19. G H What is the name of this shape? > o Trapezium 72o 49 J > I What is the value of ? 108o What is the value of ? 131o The sum of all the interior angles of a quadrilateral is............... 19
- 21. Attachments Quad Family Tree.notebook