Question

Side BC of AABC is extended to point D. The measure of ZACD is 120°. If the
interior opposite angles are in the ratio 3 : 5, then find the measure of all the angles
of the triangle.​

Answer 1

Question

Side BC of AABC is extended to point D. The measure of ZACD is 120°. If the  interior opposite angles are in the ratio 3 : 5, then find the measure of all the angles  of the triangle.​

ANSWER

40° IS THE CORRECT ANSWER

∠ACD=120d

∠ABC∠CAB=12units

∴∠ACB=180∘−120∘

∠ACB=60∘

As we know that

∠A+∠B+∠C=180∘

∠A+B=180∘−60∘

∠A+∠B=120∘

3 units=120∘

1 unit=40∘

∠ABC=1×40∘=40∘

∠CAB=2×40∘=80∘

∴∠ABC=40∘