Sec One Express Mathematics ICT Lesson Chapter 7: Angles and Parallel Lines 7.2 Angles A) Angles and Measurements We can measure a corner of Louvre Museum in Paris, France. Le us name the angle The unit of angle is degree. Example: B A C Sec One Express Mathematics ICT Lesson 7.2 Angles B) Types pf Angles Complementary angles Here are more examples types of angles Note: If the sum of two angles adds up to 90 o A D B C WHAT HAVE YOU LEARNT ? Sec One Express Mathematics ICT Lesson Let us try this Note: This is a complementary angle where the two angles adds up to 90 o Supplementary Angles Here are more examples types of angles Note: If the sum of two angles adds up to 180 o Here E F H G WHAT HAVE YOU LEARNT ? Sec One Express Mathematics ICT Lesson Let us try this Sec One Express Mathematics ICT Lesson PROPERTIES OF ANGLES B E AC D Here WHAT HAVE YOU LEARNT ? Sec One Express Mathematics ICT Lesson Let us try this The sum of adjacent angles on a straight line is 180 o. Sec One Express Mathematics ICT Lesson Sum of all angles at a point is 360 o Here 63 o + 50 o + 75 o c = 360 o Therefore c = 137 o Sum of all angles adds to 360 o Sec One Express Mathematics ICT Lesson When two straight lines intersect, the vertically opposite angles are equal. P o Q R S Reason: Vertically opposite angles. WHAT HAVE YOU LEARNT ? Sec One Express Mathematics ICT Lesson Activity I Click on the following link to recall the types of angles.Sec One Express Mathematics ICT Lesson Ace-Learning Activity Log on to your Ace-Learning account and follow the instructions Content Hub -> Exploratory Activities Sec One Express Mathematics ICT Lesson Exploratory Activities: Geometry -> Complete these 1 Adjacent angles on a straight line 2 Angles at a point 3 Vertically opposite angles Sec One Express Mathematics ICT Lesson Exploratory Activities: Alternate Angles Follow the activities in this order Exploration, Understanding & Application! Sec One Express Mathematics ICT Lesson Explore the following from Ace-learning 1 Adjacent angles on a straight line 2 Angles at a point 3 Vertically opposite angles HAVE FUN! Sec One Express Mathematics ICT Lesson