Assertion (A) : If a line make angles ${45}^0, {45}^0$ with the x and y axis respectively then it makes angle ${60}^0$ with z-axis
Reason (R) : If $\alpha ,\beta ,\gamma$ are the angles made by a line with the coordinate axes then ${\cos }^2\alpha + {\cos }^2\beta +{\cos }^2\gamma =1$

The Statement 2 is true. 

If $\alpha ,\beta ,\gamma$ are the angles made by the line with axes in the positive direction of axes, then ${\cos }^2\alpha +{\cos }^2\beta +{\cos }^2\gamma =1$

But in the statement I,  the angles are given as $45°,45°, 60°$

Hence, 

$\begin{array}{rcl}{\cos }^{2}45°+{\cos }^{2}45°+{\cos }^{2}60°& =& 1\\ \frac{1}{2}+\frac{1}{2}+\frac{1}{4}& =& 1\\ \frac{3}{4}& =& 1\end{array}$

Therefore, he angles are given as $45°,45°, 60°$ are not the measures of angles by the line with axes.