180°:pi=()°:(rad). Set (rad)=2.5 and solve for ()° degrees.
Explanation:
You probably know that 180° corresponds to pi radians;
You can build the proportion: 180°:pi=()°:(rad)
Set (rad)=2.5 and solve for ()° degrees;
you'll get: ()°=180°2.5*1/(pi)=180°2.5*1/(3.14)=143.3°