obliczanie obwodu i pola z niewiadomą x:
Ob = 6x - 1 + x + 4 + 2x + 4 + 2x + 4 = 6x + x + 2x + 2x - 1 + 4 + 4 + 4 = 11x + 11
[tex]P = \frac{(a+b)*h}{2} = \frac{(6x - 1 + x + 4)*8}{2} = \frac{(7x + 3)*8}{2} = \frac{56x+24}{2} = 28x + 12[/tex]
obliczanie obwodu i pola z x = 2:
Ob = 6*2 - 1 + 2 + 4 + 2*2 + 4 + 2*2 + 4 = 12 - 1 + 2 + 4 + 4 + 4 + 4 + 4 = 33
[tex]P = \frac{(a+b)*h}{2} = \frac{(6*2-1+2+4)*8}{2} = \frac{17*8}{2} = \frac{136}{2} = 68[/tex]
