Odpowiedź:
Zad. 8
[tex]obw = 2a + 2b\\a = 2b\\2a + 2b = 36\\6b = 36\\b = 6\\a = 12\\p = 6 * 12 = 72 cm^{2}[/tex]
Zad. 9
[tex]z tw. Pitagorasa\\3^{2} +4^{2} =a^{2} \\9+ 16= a^{2} a = 5obw = 4 * 5 = 20cm^{2}[/tex]
Zad. 10
wykładzina:
[tex]p = 4.5 * 3.5 = 15.75m^{2}[/tex]
listwa:
[tex]obw = 9 + 7 = 16m[/tex]