On a coordinate plane, triangle K J L is shown. Line segment G H goes from side J K to J L. Point K is at (0, 0), point G is at (e, f), point J is at (2 e, 2 f), point H is at (e d, f), and point L is at (2 d, 0). To prove part of the triangle midsegment theorem using the diagram, which statement must be shown? The length of JK equals the length of JL. The length of GH is half the length of KL. The slope of JK equals the slope of JL. The slope of GH is half the slope of KL.