What is the distance between the points (-4, 8) and (10,-8)?

In the diagram below? p is circumscribed about quadrilateral abcd. what is the value of x

This is a map of the mars exploration rover opportunity predicted landing site on mars. the scale is 1cm : 9.4km. what are the approximate measures of the actual length and width of the ellipse? i mostly need to know how to set it up : )

What is 617.3 miles and each gallon of gas the car can travel 41 miles select a reasonable estimate of the number of gallons of gas karl used.