At full price, Melvin would pay 1.679 dollars per liter of gasoline. Using his loyalty card, Melvin only pays 1.439 dollars per liter. How much less does Melvin pay per liter using his loyalty card?

d

because parallelagram have all 4 angels the same size dependeing and a rectangle and square are oth parallelogram

step-by-step explanation:

assume that you have 3 different side lengths.   apply the pythagorean theorem here:   square each of the two shortest sides; call them a and b, so that their squares are a² and b².   also square the longest side, calling the result c².

now, if a² + b² = c² is true, the triangle is a right triangle; otherwise it is not a right triangle.