Question 1 - Figure it out - Page 123, 124, 125 - Chapter 5 Class 7 - Parallel and Intersecting Lines (Ganita Prakash)

Transcript

Question 1 Find the angles marked below. By alternate interior angles ∠ a = 48° By alternate interior angles ∠ b = 52° Here, ∠ c and 81° are alternate interior angles ∠ c = 81° Here, ∠ d and 99° are alternate interior angles ∠ d = 99° Here, ∠ e and 99° are alternate interior angles ∠ e = 69° Note: There are two transversals made, ignore the left one and only focus on right one – then ∠ e and 69° would be alternate interior angles Here, ∠ f and 132° are interior angles on same side of transversal So, their sum is 180° ∠ f + 132° = 180° ∠ f = 180° – 132° ∠ f = 48° Here, ∠ g and 122° are corresponding angles ∠ g = 122° Here, ∠ h and 75° are alternate interior angles ∠ h = 75° Note: There are two transversals made, ignore the left one and only focus on right one – then ∠ h and 75° would be alternate interior angles Here, ∠ i and 54° are alternate interior angles ∠ i = 54° Hint: Make the figure again (by tracing) with only ∠ i marked, then it will be easier to solve Here, ∠ j and 97° are alternate interior angles ∠ j = 97° Note: You can also do by Sum of angles of triangle = 180° One angle is 27°, other is ∠ j and another is linear pair of 124° (i.e. 180° – 124°). Putting sum = 180° we will get ∠ j