The area would be 35 cm squared.
Lets break it down:
Triangle- The area of a triangle is base×height÷2
so if we plug in the numbers, the base would be 5 (the length) and the height would be 4 (the height). 5×4= 20÷2= 10.
Square- The area of a square is base×height so if we pluged in the numbers, the base is 5 (the length) and the height is 5 (the height). 5×5= 25.
10+25= 35 cm squared
Hope this helps!