16Hit1600
Geometry and TrigonometryHardMidsegment of a triangle

Geometry and Trigonometry practice question

In triangle ABC, point D is the midpoint of side AB and point E is the midpoint of side AC. If DE = 7, what is the length of BC?

Answer: 14

The segment joining the midpoints of two sides of a triangle is parallel to the third side and half its length. So BC = 2 × DE = 14.

Common wrong answers

If you answered 7
7 is DE itself; BC is twice as long.
If you answered 21
21 triples DE; the midsegment is exactly half the third side.
If you answered 3.5
3.5 halves DE, but DE is the half; the third side is the double.

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