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Class 10 · Mathematics (Basic) · Unit 6: Triangles

Basic Proportionality Theorem (Thales)

Lesson 2 of 6
If a line is drawn parallel to one side of a triangle and intersects the other two sides in distinct points, then it divides those two sides in the same ratio: in △ABC\triangle ABC with DE∥BCDE\parallel BC, AD/DB=AE/ECAD/DB = AE/EC.
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