Question 111795
the difference between the height of the bullet hole (90 in) and the presumed height of the muzzle (48 in) is 42 in


this is the length of the side of a right triangle that is opposite the 34° angle of elevetion of the muzzle
___ the right triangle is formed by the wall; the horizontal distance from the wall to the muzzle;
___  and the distance from the muzzle to the bullet hole


using trigonometry; the side opposite the 34° angle, divided by the distance to the wall, is the tangent of the angle
___ so the distance to the wall is (42 in)/(tan 34)