Answer
$\color{blue}{\approx 0.3134 \text{ radians}}$
Work Step by Step
RECALL:
(1) $1^0=60'$
(2) To convert an angle in degrees to radians, multiply $\dfrac{\pi}{180^o}$ then simplify.
Convert $25'$ to degrees to obtain:
$25' = 25' \cdot \dfrac{1^o}{60'} = \dfrac{5}{12}^o$
Thus, the given measurement is equivalent to $56\frac{5}{12}^o$
Convert to radians using the formula in (2) above to obtain:
$\require{cancel}
56\frac{5}{12}^o
\\= 56\frac{5}{12}^o \cdot \dfrac{\pi}{180^o}
\\=0.3134259259
\\\color{blue}{\approx 0.3134 \text{ radians}}$
