Can anyone help me I really need your help if anyone helps me they can be my friend

Arectangular exercise mat has a perimeter of 36 feet the length of the mat is twich the width writeand solve an equation to determine the length in feet. of the mat then find the area in square feet of the mart

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

What two criteria are needed for triangles to be similar