Oznaczenia jak na rysunkach w załączniku.
Jednostka: 2 kratki = 1 cm
a)
[tex]P_F = P_I + P_{II} = a \cdot h_1 + \frac{1}{2} ah_2 = 2 \cdot 1,5+ \frac{1}{\not{2}_1} \cdot \not{2}^1 \cdot 1= 3 + 1 = 4 \ cm^2 \\\\ \boxed{P_F = 4 \ cm^2}[/tex]
b)
[tex]P_F = P_I + P_{II}+ P_{III}= \frac{a + b}{2} \cdot h_1+ ca+ \frac{1}{2}ah_2= \frac{3 + 1}{\not{2_1}} \cdot \not{2}^1+ 1,5 \cdot 3 +\\ + \frac{1}{\not{2}_1} \cdot \not{3}^{1,5} \cdot 1,5 =4 +4,5 + 2,25 = 10,75 \ cm^2 \\\\ \boxed{P_F = 10,75 \ cm^2}[/tex]
c)
[tex]P_F = P_I + P_{II}= \frac{a + b}{2} \cdot h_1 + ch_2 = \frac{3+2,5}{\not{2}_1} \cdot \not{2}^1+2 \cdot 2 = 5,5 + 4 = 9,5 \ cm^2 \\\\ \boxed{P_F = 9,5 \ cm^2}[/tex]
d)
[tex]P_F = P_I + P_{II}+ P_{III}= \frac{a+b}{2} \cdot h_1 + ca + \frac{d+e}{2} \cdot h_2 = \frac{2,5+1,5}{2} \cdot 1 + 2 \cdot 2,5+ \frac{1+2}{\not{2}_1} \cdot \not{4}^2 = \\ = \frac{4}{2}+ 5 + 3 \cdot 2 = 2 + 5 + 6 = 13 \ cm^2 \\\\ \boxed{P_F = 13 \ cm^2}[/tex]
