Question

Expresse em graus ---> Pin sobre 2 .
Expresse em graus --> 3Pin sobre 4.

Answer 1

Para transformar um número real (em radianos) para graus (e vice-versa):

$1\text{ (rad)}=\dfrac{180^{\circ}}{\pi}\;\;\Leftrightarrow\;\;1^{\circ}=\dfrac{\pi}{180}\text{ (rad)}$


a) $\dfrac{\pi}{2}$

$\dfrac{\pi}{2}\text{ (rad)}\\ \\ =\dfrac{\pi}{2}\cdot \dfrac{180^{\circ}}{\pi}\\ \\ =\dfrac{\diagup\!\!\!\!\pi\cdot 180^{\circ}}{2\cdot \diagup\!\!\!\!\pi}\\ \\ =\dfrac{180^{\circ}}{2}\\ \\ =90^{\circ}$


b) $\dfrac{3\pi}{4}$

$\dfrac{3\pi}{4}\text{ (rad)}\\ \\ =\dfrac{3\pi}{4}\cdot \dfrac{180^{\circ}}{\pi}\\ \\ =\dfrac{3\diagup\!\!\!\!\pi\cdot 180^{\circ}}{4\cdot \diagup\!\!\!\!\pi}\\ \\ =\dfrac{540^{\circ}}{4}\\ \\ =135^{\circ}$