[tex]a)\\a = 6cm\\b = 3cm\\H=12cm\\Pc=2Pp+Pb\\Pp=a*b\\Pb=2aH+2bH\\Pc=2*6cm*3cm+2*6cm*12cm+2*3cm*12cm=2*18cm^2+2*72cm^2+2*36cm^2=36cm^2+144cm^2+72cm^2=252cm^2[/tex]
b)
[tex]H=7cm\\a = 5cm\\b = 12cm\\c^2=a^2+b^2\\c^2=5^2+12^2\\c^2=25+144\\c^2=169\\c=\sqrt{169}=13\\Pc=2Pp+Pb\\Pp=\frac{ab}2\\Pb=aH+bH+cH\\Pc=2*\frac{5cm*12cm}2+5cm*7cm+12cm*7cm+13cm*7cm=60cm^2+35cm^2+84cm^2+91cm^2=270cm^2[/tex]
[tex]c) \\a=9cm\\H=13cm\\Pc=2Pp+Pb\\Pp=a^2\\Pb=4aH\\Pc=2*(9cm)^2+4*9cm*13cm=2*81cm^2+4*117cm^2=162cm^2+468cm^2=630cm^2[/tex]
[tex]d)\\a=7cm\\H=15cm\\Pp=\frac{a^2\sqrt3}4\\Pb=3aH\\Pc=2Pp+Pb\\Pc=2*\frac{(7cm)^2\sqrt3}4+3*7cm*15cm=\frac{49cm^2\sqrt3}2+315cm^2=24.5\sqrt3cm^2+315cm^2[/tex]