P=(a+b) *h/2
2
a)
[tex]p = \frac{(5 + 7) \times 4}{2} = \frac{12 \times 4}{2} = \frac{48}{2} = 24 {cm}^{2} [/tex]
b)
[tex]p = \frac{(10 + 20) \times 12}{2} = \frac{30 \times 12}{2} = \frac{360}{2} = 180 {mm}^{2} [/tex]
c)
[tex]p = \frac{(8 + 4) \times 3}{2} = \frac{12 \times 3}{2} = \frac{36}{2} = 18 {cm}^{2} [/tex]
Pozdrowionka! ~Wika
