Verified answer

[tex]a) \: \: a = \frac{b \times h}{2} [/tex]

[tex]a = \frac{4.8 \times 4.2}{2} [/tex]

[tex]a = \frac{20.16}{2} [/tex]

[tex]a = 10.08m {}^{2} [/tex]

[tex]b) \: \: a = \frac{4 \times 2.7}{2} [/tex]

[tex]a = \frac{10.8}{2} [/tex]

[tex]a = 5.4m {}^{2} [/tex]

[tex]c) \: a = \frac{5 \times 3.3}{2} [/tex]

[tex]a = \frac{16.5}{2} [/tex]

[tex]a = 8.25 m{2} [/tex]