Area of a Trapezium / Challenge Maths / Competition Maths

Gina has a window in her house in the shape of an equilateral triangle. The height of the window is 48 inches. She has a window shade that rises from the bottom of the window upward. When the height of the shade is ℎ inches, the total area covered by the shade is given by the .. ‪@skoolmaths‬