Finding Acceleration on 30° Downward Slope w/ 0.10 Coeff. of Friction

[homevolend]

Homework Statement

A person is running down a hill which is a 30° downward slope. If the coefficient of kinetic friction is 0.10, what is acceleration of the runner.

Homework Equations

Fnet=F┴-Ff

The Attempt at a Solution

Since we are only given 2 known things, the θ is 30° and the kinetic friction is 0.10. I am wondering if I am using the correct formula and need to be pointed in direction of what else to find to actually find the acceleration. I know we need Fnet but that is not all.

 

[homevolend]

Ok I have found out the answer one way by just doing a = 9.81 x (0.5-0.10(0.866)) but is there a different way to find the answer or is this the only one? I mean by finding Fnet and somehow answering it a different way?