Call the angle of elevation A. The ramp is the hypotenuse of a right triangle with acute angle A. The length of the side opposite angle A equals the height above the ground of the other end of the ramp, so $\displaystyle{o}={1}\usepackage{cmbright}\Huge\$ . The length of the side adjacent to angle A equals the horizontal distance to the building, so $\displaystyle{a}={10}\usepackage{cmbright}\Huge\$ . This means that:

$\displaystyle{\tan{{A}}}=\frac{{o}}{{a}}=\frac{{1}}{{10}}={0.1}\usepackage{cmbright}\Huge\$

So: $\displaystyle{A}={{\tan}}^{{-{1}}}{0.1}={{5.710593138}}^{\circ}\approx{{6}}^{\circ}\usepackage{cmbright}\Huge\$