The radius of the base of a cylindrical silo is 28 feet. If the distance from point B to the silo is 53 feet, what is the distance from point B to point A, a point of tangency?

1 answer

Having seen this problem many many times, consider a top view with O the centre of the silo
then OB = 28+53 = 81 ft
and OA = 28 ft
we have a right-angled triangle, since a tangent meets its radius at 90°
BA^2 + 28^2 = 81^2
BA^2 = 5777
BA=76.007 or appr 76 ft