CK12 - Trigonometry

Thesetrianglesare similar. This meansthat the correspondinganglesare congruent,and the corresponding
sidesare proportional.In the trianglesshownabove,we havethe following:

Threepair of congruentangles: , and

The ratiosof sideswithinone triangleare equalto the ratiosof sideswithinthe secondtriangle:

, and

The ratiosof correspondingsidesare equal:

, and

Example4:In the trianglesshownabove, , and. Whatare the
lengthsof sidesDFandEF?

Solution:EF= 3.5 andDF= 2.5.

Giventhat , we have.

Similarly, as , we have