What is the answer please help no links I will report

A20? -foot ladder is placed against a vertical wall of a? building, with the bottom of the ladder standing on level ground 19 feet from the base of the building. how high up the wall does the ladder? reach?

Module 10 coordinate proof using slope and distance answers is quadrilateral abcd a parallelogram? explain how you know.

Which equation results from adding the equations in this system? x+6y=9 and -x+2y=-15