Question

Rebecca has a triangular piece of board. She cut it along a line parallel to the base of the triangle as shown below.

What is the length of the line along which she cut the board?

Answer 1

@TuringTest

Answer 2

10/20 = 4/x; 1/2 = 4/x; x=8. Use the concept of similar triangles.

Answer 3

thank you!