Data:
u=0 m/s is the initial velocity of the plane
v=62 m/s is the final velocity of the plane (at which the plane takes off)
a=1.7 m/s^2 is the acceleration of the plane
To find the minimum distance S the plane needs to take off, we can use the following equation:

Re-arranging it and substituting the numbers, we find

The collapsed answer of Penchalreddy Badepalli is correct. The composition of two reflections via two mirror making an angle \alpha is equivalent to a single rotation by an angle 2\alpha, hence 2 * 60 deg = 120 deg. And turns is independent of the absolute orientation of the two mirrors in space and/or the direction of incidence of the incoming ray.
One could use elementary geometry to prove this (if you presume the direction of incidence is irrelevant imagine hitting the first mirror at 90 deg, then going retro right back along the normal to the first mirror, and follow the directions).
The smallest level of ordination in living things. Every living thing is made up of atoms. Atoms are made up of protons, neutrons, and electrons.