Does anyone know any good websites for geometry i really need

Simplify. (-2)^-3 a. -8 b. -1/8 c. 1/8 d. 8

Afarm is to be built in the shape of quadrilateral abcd, as shown below. all four sides are equal. a rhombus abcd is shown with diagonal ac equal to 15.5 feet and diagonal bd equal to 13.2 feet. what is the area of the farm? pleas only pick from the 4 below 62 square feet 52.8 square feet 57.4 square feet 102.3 square feet

If x varies directly as y, and x = 7.5 when y = 10, find x when y = 4