Someone help ME PLZ

What is the square root of 45? (step by step working plz)

Television sizes are based on the length of the diagonal of the television's rectangular screen. so, for example, a 70-inch television is a television having a diagonal screen length of 70 inches. if a 70 inch television's diagonal forms a 29°angle with the base of the screen, what is the vertical height (1) of the screen to the nearest inch? 70 inhin

What are the solutions of the system? solve by graphing. y = -x^2 - 3x + 2 y = -2x + 2