5-13b exploring the sum of a triangles angles

Conjecture 4: In any triangle, the segment whose endpoints are the midpoints of two sides of the triangle is half the length of the third side. Conjecture 5: Given a value r between 0 and 1. In any triangle, the segment whose endpoints are r times the length of the respective side from a given vertex has length r times the length of the third side. ................
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