Can help me with this?

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

Jonah runs 3/5 miles on sunday and 7/10 mile on monday. he uses the model to find that he can ran a total of 1 mile . what mistake does jonah make

What is the length of the unknown leg in the right triangle ?