5.
a)
a = 5 cm
b = 12 cm
h = 3 cm
[tex]P = \frac{(a+b)h}{2}=\frac{(5+12)\cdot 3}{2}= \frac{17\cdot 3}{2}=51/2=25,5 \text{cm}^2[/tex]
b)
a = 6cm
h = 4cm
[tex]P = ah = 4 \cdot 6 = 24 \text{ cm}^2[/tex]
c)
e = 5cm
f = 7 + 2 = 9 cm
[tex]P = \frac{ef}{2}=\frac{5\cdot 9}{2} = 45/2=22,5 \text{ cm}^2[/tex]
6.
e = 18 cm
f = 24 cm
a = 15 cm
h = ?
Pole rombu można policzyć na dwa sposoby:
[tex]1. P = \frac{ef}{2}\\2. P = ah[/tex]
Licząc wzorem 1 mamy:
[tex]P = \frac{18 \cdot 24}{2}=216 \text{ cm}^2[/tex]
Licząc wzorem 2:
[tex]P = 15 \cdot h = 216 \\15 \cdot h = 216 /:15\\h = 14,4 \text{ cm}[/tex]
