Solve for adjacent side length: Angle is 36 degrees, opposite side is 120 inches?

Question

I need to solve for the run of a set of stairs.  I have the rise: 120".  I have the angle: 36 degrees.  I know that I can use TAN36 = opposite over adjacent, but the simple mechanics of doing this eludes me, as the last time I did this, it was 1991.  Please help.

Answer 1

????????? maebee yu wanna find the RUN ??????????

folks hu make thangs yuze werds "run" & "rise" for thangs that go up at a slope

run=the horizontal part (along the floor or the dirt)

riss=the up part

yu sae angel=36 deg...me assume thats from floor up tu the staers

Yu sae the rise=120 inch...thats the vertikal part

vertikal=rise=diagonal*sine(angel)=120...impli diagonal=rise/sine(36)=120inch/sine(36)

sine(36)=0.5877852522924731

diagonal=120/0.587785...or=1.7013016166822938*120

=204.15619400187526 inch, or bout 204 inch

run=diagonal*kosine(angel)=204*kosine(36)

kosine(36)=0.8090169943749474

run=204*0.809016...

=165.03946685248928