Congruent acute or obtuse angles

The image of my roof has two congruent acute angles(angles 1 and 2). The two base angles are acute which means they are less than 90 degrees. The two base angles are congruent which means that there angle measures are equal to each other. The base angles must be congruent so the weight of the roof is split evenly. Roofs are used on most buildings in the world to give shelter from rain, sleet, snow, wind, hail and other elements. Carpenters, roofers, architects and engineers use this design in constructing buildings.

This photo was taken from my driveway viewing my room's window.