Question

what is basis proportionality theorem​

Answer 1

Answer:

The intercept theorem, also known as Thales's theorem, basic proportionality theorem or side splitter theorem is an important theorem in elementary geometry about the ratios of various line segments that are created if two intersecting lines are intercepted by a pair of parallels.

Answer 2

Answer:

If a line is drawn parallel to third side then it divides the triangle in ratios.

this is given by person named Thales.

so even called Thales theorem.