Elana’s backyard is in the shape of a rectangle. She created a triangular-shaped flower bed (shown as the shaded region) to plant flowers in. The area of the triangular flower bed is square feet. The area of her backyard that does not include the flower bed is square feet. Answer please

“exterior angles of triangles. an exterior (or external) angle is the angle between one side of a triangle and the extension of an adjacent side. try this drag the orange dots on any vertex to reshape the triangle.” look to get to the answer i explained what it means and other things i hope it you .