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Problem 439

Geometry Difficulty 2.2 Multiple choice CEMC Fermat · Canada · 2013

In the diagram, rectangle PQRSPQRS has PQ=30PQ=30 and rectangle WXYZWXYZ has ZY=15ZY=15.

Figure 0
If SS is on WXWX and XX is on SRSR so that SX=10SX=10, then WRWR equals

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Official solution

Since PQRSPQRS and WXYZWXYZ are rectangles, then SR=PQ=30SR = PQ=30 and WX=ZY=15WX = ZY = 15.

Since SX=10SX=10, then WS=WX−SX=15−10=5WS = WX-SX=15-10=5.

Thus, WR=WS+SR=5+30=35WR = WS+SR=5+30=35.

Source: CEMC, University of Waterloo, licensed CC-BY-NC-4.0. Statement reproduced verbatim; metadata (topic, difficulty, ordering) added by this project.