Zee Right Trianglee

Right Triangles

Trig relations can be used to find unknown parts of right triangles. 

                sinѲ=opposite/hypotenuse

                cosѲ=adjacent/hypotenuse

                tanѲ=opposite/adjacent

1)       In ∆ABC, angleA=90˚, angleB=25˚, and a=18.  Find b and c.

Side a is hypotenuse, side b is opposite, and c is adjacent.

Tan 25˚=b/18,  b=8.39

Cos25˚=c/18,  c=16.31

2)       In ∆DEF, angle D=90˚, angle E=12˚, and e=9.  Find d and f

Side e is opposite, side d is hypotenuse, and side f is adjacent.

Tan 12˚=9/f,  f=9/tan12˚, f=42.34

Sin 12˚=9/d, d=9/sin 12˚, d=43.29

There are reciprocal functions also

                secѲ=hypotenuse/adjacent

                cscѲ=hypotenuse/opposite

                cotѲ=adjacent/opposite

All right triangles can be solved with sin, cos, and tan but the reciprocal functions due exist.

Lovee,

Jenna Roussel