20cm- 1 przyprostokątna
20-5= 15cm - 2 przprostokatna
[tex] {a}^{2} + {b}^{2} = {c}^{2} \\ {20}^{2} + {15 }^{2} = {c}^{2} \\ 400 + 225 = {c}^{2} \\ c = \sqrt{625} = 25cm[/tex]
odp A 25cm
