Abstract: The inventive concept presented is a trench slope angle tool and the method for using the slope angle tool during the excavation of a trench in a particular type of soil. In essence the slope angle tool is a planar, hand-held sighting device having a handle integrally attached to a Y-shaped component. The device may be utilized by a construction worker or project supervisor (the “user”) at a trenching worksite. The user visually superimposes the slope and banks of the trench against the contours of the slope angle tool to determine compliance with government-regulated excavation standards. Other important construction safeguards and govemmentally-regulated standards are also displayed on each face of the slope angle tool. In this manner, the correct trench sidewall slope, “spoil” pile locations, and other safety requirements can be readily observed to determine whether these elements are in compliance with the governmental regulations.