How do I find out how to solve a triangle

To solve a triangle you find all missing sides and angles.

For a right triangle use

Cos (angle) = adjacent/hypotenuse

Sin (angle) = opposite/hypotenuse

Tan (angle) = opposite/adjacent

Opposite ^2 + adjacent^2 = hypotenuse^2

For non right triangles

Law of sines

SinA/a=SinB/b=SinC/c

Law of cosine

a^2 = b^2+c^2-2bcCosA

What exactly are you asking. Are you asking for area or perimeter?