Prove that a line parallel to one side of a triangle divides the other two sides proportionally. Be sure to create and name the appropriate geometric figures

Question

anonymous · Answer

How am I supposed to put my answer in words :/

dumbcow · Answer

proof involves AA similar triangles postulate and corresponding angle thm

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First show that angles C and E are congruent because they are corresponding angles
Next show that triangle ADE is similar to triangle ABC because 2 angles are congruent (AA postulate)
Similar triangles have proportional sides