Question

Convert $40^{\circ}20'$ into radian measure.

• A. $111\,\pi / 540$
• B. $121\,\pi / 540$
• C. $131\,\pi / 540$
• D. $128\,\pi / 541$

Answer 1

Answer: (B)

$121\,\pi / 540$

Answer 2

We know that $180^{\circ}=\pi$ radian Hence $40^{\circ}20'=40 \frac{1}{3}$ degree $=\frac{121 \pi}{540}$ radian Therefore $40^{\circ}20'=\frac{121\pi}{540}$ radian.