Question

Geometry help please

Answer 1

Answer:  RJ = 10

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Explanation:

Recall that midsegments are half as long as the side they are parallel to. In this case, midsegment PQ is parallel to segment GJ. This means PQ is half as long as GJ. Phrased another way, we can say GJ is twice as long as PQ.

So,

GJ = 2*PQ

Also, we can see that GR = RJ due to the triple tickmarks they share. This leads to GJ = GR+RJ = RJ+RJ = 2*RJ

Or in short,

GJ = 2*RJ

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In summary we can see that

• GJ = 2RJ
• GJ = 2PQ

equating both right hand sides leads to

2RJ = 2PQ

RJ = PQ

Because PQ is 10 units, this means RJ is also 10 units.

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Another way to see why PQ = RJ is to notice how triangles HPQ and QRJ are congruent triangles (use SAS to prove this). The corresponding pieces PQ and RJ are the same length, so PQ = RJ = 10.