Q3 of 23 Page 21

In figure 2.20, if ∠ a≅ ∠ b and ∠ x≅ ∠ y then prove that line L ∥ line N.

Given ∠ a≅ ∠ b and ∠ x≅ ∠ y

To find: line L ∥ line N


∠ a≅ ∠ b (given)


But they form a pair of corresponding angles which are congruent


Line L ∥ line M …………... (1)


∠ x≅ ∠ y (given)


But they form a pair of alternative angle that are congruent


Line M ∥ line N (alternative angle) ………… (2)


Equation (1) and equation (2)


Line L ∥ line N (hence proved).


More from this chapter

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1

In figure 2.18, y = 108°. and x = 71° Are the lines m and n parallel? Justify?

 2

In figure 2.19, if ∠ a≅ ∠ b then prove that line L ∥ line M.

 4

In figure 2.21, if ray BA || ray DE, ∠ c = 50° and ∠ D = 100°. Find the measure of ∠ ABC.


(Hint: Draw a line passing through point C and parallel to line AB.).

 5

In figure 2.22, ray AE || ray BD, ray AF is the bisector of ∠ EAB and ray BC is the bisector of ∠ ABD. Prove that line AF || line BC.