\(a,Xét.\Delta ABH.có:\\ AB^2=AH^2+HB^2\rightarrow17^2=15^2+HB^2\\ \Rightarrow HB^2=AB^2-AH^2=17^2-15\\ =64\rightarrow8^2=8cm\\\Rightarrow BC=BH+HC=8+22=30\)
b) + c) nhường bạn khác nha:)
b: \(AC=\sqrt{15^2+22^2}=\sqrt{709}\left(cm\right)\)
\(BH=\sqrt{17^2-15^2}=8\left(cm\right)\)
=>BC=30(cm)
\(C=30+17+\sqrt{709}=47+\sqrt{709}\left(cm\right)\)