found this online, hope it helps !!
I) 4

The number of sides=

The number of sides =8 sides
ii) 3

The number of sides=

The number of sides= 12
314x5es la altura de la dimensión
¹/₄y + 9 = ½
¹/₄y = ½-9
¹/₄y = -¹⁷/₂
y = -34

Area of shaded region = 34 cm²

Area of shaded region = Area of bigger rectangle - Area of smaller rectangle.
Area (big) :


Area (small) :


Area of shaded region :



Area of shaded region = 34 cm²