What is the circumference of a child's swimming pool that has a radius of 3 feet

Write the slope-intercept form of the line that passes through the point (1, 0) and is parallel to x - y = 7. t

Which one ? is the answer and how to find this answer

Use the formulas a = x 2 – y 2, b = 2xy, c = x 2 + y 2 to answer this question. one leg of a right triangle has length 11 and all sides are whole numbers. find the lengths of the other two sides. the other leg = a0 and the hypotenuse = a1