Question

Find the length x.
4
3.5
2
O
X

Answer 1

so we have two triangles touching each other at a point on that vertical line, and the angles on either side of the vertical line are vertical angles and thus congruent, which means both triangles are similar by AA.

`\cfrac{4}{2}=\cfrac{x}{3.5}\implies 2=\cfrac{x}{3.5}\implies 7=x`