After it dried, which took about two hours, I sanded it flush with the wood using #120-grit sandpaper, then stained the entire shelf. You have to look closely to see the spot where the nail hole had been! Quick Tip: Always sand in the direction of the grain of the wood to avoid unsightly scratches.
In the picture below, the angles â ABC, â BCA and â CAB are the three interior angles of the triangle. An exterior angle is formed by extending one of the sides of the triangle; the angle between the extended side and the other side is the exterior angle. In the picture, angle â ACD is an exterior angle. Euclid's exterior angle theorem
Angles and Sides of a Triangle. 1  The interior angles of a triangle are always added up to 180 degrees. The exterior angle of a triangle is equal to the sum of the two interior angles that are not adjacent to it.  The sum of the lengths of any two sides of a triangle is always larger than the length of the third.