Question

Find the degree measure of ${\left(\frac{\pi }{9}\right)}^c$ and ${\left(-\frac{\pi }{3}\right)}^c$ respectively.

• A. $20^{\circ }$, $-60^{\circ }$
• B. $30^{\circ }$, $60^{\circ }$
• C. $20^{\circ }$, $40^{\circ }$
• D. $40^{\circ }$, $50^{\circ }$

Answer 1

Answer: (A)

(i) ${\left(\frac{\pi }{9}\right)}^c={\left(\frac{180}{\pi }\times \frac{\pi }{9}\right)}^{\circ }$
$={\left(\frac{180}{9}\right)}^{\circ }=20^{\circ }$
(ii) ${\left(-\frac{\pi }{3}\right)}^c={\left(\frac{180}{\pi }\times \left(\frac{\pi }{3}\right)\right)}^{\circ }$
$=-60^{\circ }$.