Ok ,so here's an another interesting question for u all

area of the polygon = area of trapezium + area of the square
                                =1/2 * 11 cm * (8 + 2cm) + 5 cm * 5 cm
                                =1/2*10 cm * 11 cm + 25 cm2
                                = 55 cm² + 25 cm²
                                = 80 cm
GIVE A THUMBS UP IF YOU UNDERSTOOD THE ANSWER:)