A city planner marks two straight guide lines and on the ground to indicate where…

MATHEMATICS · Multi-part · CBSE · Mathematics · Lines and Angles · Lines and Angles

Problem

A city planner marks two straight guide lines g1g_1 and g2g_2 on the ground to indicate where future bicycle lanes will run. A surveyor’s measuring pole pp crosses both guide lines. At the intersection with g1g_1, the angle between the pole and the guide line on the north-east side is measured as 68∘68^\circ. At the intersection with g2g_2, the angle between the pole and the guide line on the south-west side is also found to be 68∘68^\circ. Answer the following questions. (i) Identify the special pair of angles that are equal in this situation. (ii) Explain, with reason, whether the two guide lines g1g_1 and g2g_2 must be parallel. (iii) Name the theorem that justifies your answer in part (ii).

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