Imagine cutting a member under [[Force|tension]] or compression at an angle. The resulting [[Normal Stress|normal]] and [[Shear Stress|shear]] stress relative to the cut will be different from the normal stress applied to the member. ![[oblique.png]] $σ=\dfrac{F\cos\theta}{A/\cos\theta}=\dfrac{F{\cos}^2 \theta}{A}$ $\tau=\dfrac{F\sin⁡\theta}{A/\cos⁡\theta}=\dfrac{F\sin⁡\theta\cos⁡\theta}{A}$