1. Triangle

[tex]28 {cm}^{2} [/tex]

2.Semicircle

[tex]A = 25.12{cm}^{2} [/tex]

3. Square

[tex]A = 81 {cm}^{2} [/tex]

Step-by-step explanation:

1. Triangle b = 7 cm h=8cm

[tex]A = \frac{bh}{2} \\ A = \frac{(7)(8)}{2} \\ A = \frac{56}{2} \\ A = 28 {cm}^{2} [/tex]

2. Semi-circle r= 4cm

[tex]A = \frac{\pi {r}^{2} }{2} \\ A = \frac{(3.14)( {4}^{2}) }{2} \\ A = \frac{50.24}{2} \\ A = 25.12 {cm}^{2} [/tex]

3. Square s= 9cm

[tex]A = {s}^{2} \\ A = {9}^{2} \\ A = 81 {cm}^{2} [/tex]