A carpenter wishes to ensure that two wooden rails

MATHEMATICS · Multi-part · GCSE · Mathematics · Geometry and Measures · Geometry and Measures

Problem

A carpenter wishes to ensure that two wooden rails, aa and bb, remain parallel while constructing a ladder. He places a straight plank cc across the rails so that it meets rail aa at MM and rail bb at NN. He measures the interior angles on the same side of the plank and finds them to be 64∘64^{\circ} and 116∘116^{\circ} respectively. (i) Verify, with appropriate calculation, whether the pair of interior angles measured is supplementary. (ii) Based on your verification, state whether the rails aa and bb are parallel. Give a clear reason. (iii) If another plank dd is placed so that it meets rails aa and bb on the opposite side of plank cc, what should be the sum of the interior angles formed on the same side of plank dd in order to keep the rails parallel? Explain briefly.

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