Answer:
66 cm squared
Explanation:
split the shape into 2 rectangles, then use the numbers given to solve for the new shapes
3cm by 7cm for one and 5cm by 9 cm for the other (there are multiple ways to split the shape)
multiply those numbers
3 x 7 = 21cm ^2
5 x 9 = 45cm ^2
add them together
66cm ^2 (squared)