The Pythagorean theorem states:

where a and b are the legs and c is the hypotenuse of a right triangle.
In triangle EDF, DE = 29 is the hypotenuse, and FE = 20 and DF are the legs. Substituting this information into the formula and solving for DF, we get:
![\begin{gathered} DE^2=FE^2+DF^2 \\ 29^2=20^2+DF^2 \\ 841=400+DF^2 \\ 841-400=DF^2 \\ \sqrt[]{441}=DF \\ 21=DF \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/mzkgwd6zeum4a6fi0rvysnaqnv7dk65so1.png)
Sine formula

Considering angle D, the opposite side is FE, then:

Considering angle E, the opposite side is DF, then:

Cosine formula

Considering angle D, the adjacent side is DF, then:

Considering angle E, the adjacent side is FE, then:

Tangent formula

Considering angle D, the opposite side is FE and the adjacent side is DF, then:

Considering angle E, the opposite side is DF and the adjacent side is FE, then:
