[tex]1. \\P = 3^2 = 9cm^2\\Ob = 4*3=12cm\\\\2. \\1dm = 10cm\\P = 10*5=50cm^2\\Ob = 2*10+2*5=20+10=30cm\\\\3. \\\\60mm=6cm\\0,3dm=3cmP = a*h\\P=6*3=18cm^2\\Ob = 2*4+2*6=8+12=20cm\\\\4. \\P = 6*8/2=6*4=24cm^{2}\\Ob = 6+8+10=24cm\\\\5. \\P=(4+10)*4/2=14*4/2=14*2=28cm^{2}\\Ob = 4+10+5+5=14+10=24cm\\\\6. \\P=6*8/2=6*4=24cm^2\\\\7.\\P=10*8/2=10*4=40cm^{2}\\\\8. \\1a = 100m^{2}\\P=4*25=200m^{2}\\P=2a\\\\9. \\1ha = 10000m^{2}\\P = 40*250=10000m^{2}\\P = 1ha[/tex]
