tolong ya, pakai cara kerjanya

[tex]ab = 40 \times 3 = 120km \\ bc = 50 \times 1 = 50km \\ \\ {ac}^{2} = {120}^{2} + {50}^{2} \\ {ac}^{2} = 14.400 + 2.500 = 16.900 \\ ac = \sqrt{16.900} = 130km[/tex]