Which description does not guarantee that a quadrilateral is a rectangle?
a a quadrilateral with all four angles right
b a parallelogram with congruent sides
c a quadrilateral with diagonals that are congruent and bisect each other
d a quadrilateral with all congruent angles

Grace is standing 18 feet from a lighthouse and kelly is standing 10 feet from grace. the angle that grace looks up to see the top of the lighthouse is 45°. the angle that kelly looks up to see the top of the lighthouse is y°. find the height, h, of the lighthouse. find the angle, rounded to the nearest tenth of a degree, in which kelly looks up to the top of the lighthouse. to the nearest tenth of a degree, find the value of x° . in two or more sentences, explain your calculations