Rick builds new homes for Eastover Construction Company. Yesterday, Rick installed a horizontal support beam parallel to the base of a triangular roof. Then, Rick installed a vertical support beam between the top and base of the roof, perpendicular to the horizontal beam and the base of the roof. Along the vertical beam, the distance from the top of the roof to the horizontal beam is 28 feet, and the distance from the horizontal beam to the base of the roof is 42 feet. The base of the roof is 90 feet long.
what is the length of the horizontal beam