a)
[tex]P = \frac{(6+4)*2}{2} = 6+4 = 10cm^2[/tex]
b)
[tex]P = \frac{4*6}{2} = 2*6=12cm^2[/tex]
c)
[tex]P = \frac{7*2}{2} = 7cm^2[/tex]
d)
[tex]P = 3*3=9cm2[/tex]
e)
[tex]P = \frac{4*1}{2} + 4*1 + \frac{2*1}{2} + \frac{2*2}{2} = 2+4+1+2=9cm^2[/tex]
f)
[tex]P = \frac{6*3}{2} - (\frac{(2+1)*1}{2} + \frac{1*1}{2}) = 9 - (\frac{3}{2} + \frac{1}{2}) = 9 - 2 = 7cm^2[/tex]
