Three sides of a triangle are a,3a, and root 10a.Find the measurement of angle opposite to the largest side Share with your friends Share 6 Manbar Singh answered this Let In △ ABC, AB = a, BC = 3a and AC = 10 a Now, AB2 + BC2 = a2 + 3a2 = a2 + 9a2 = 10a2and AC2 = 10 a2 = 10 a2Since AB2 + BC2 = AC2 then, △ ABC is a right angled △.Such that ∠B = 90° By the converse of pythagoras theorem∴ AC is the longest side of △ ABC & the angle opposite to the longest side is 90°. 12 View Full Answer Sumukh answered this 90 degree. 2