Un même angle mesure d degré ou \(\alpha\) radian
Compléter
\(\frac{\cdots}{180}=\frac{\cdots}{\pi}\)
\(360\mapsto 2\pi\)
\(d \mapsto \alpha\)
\(\alpha \times 360 = d \times 2\pi\)
\(\iff \alpha \times 180 = d \times \pi\)
\(\iff \frac{\alpha}{\pi} = \frac{d}{180}\)