Question

if you answer right will mark you as brainlist.​

Answer 1

Answer:

Step-by-step explanation:

Let the common multiple be x.

Therefore,

∠ BAC = 5x

∠ ACB = 7x

∠ CBA = 6x

In Triangle ACB,

∠A + ∠B + ∠C = 180

5x + 7x + 6x = 180

18x = 180

x = 10

Therefore,

∠ C = 7 × 10 = 70

But,

∠ ACB = ∠ ECD  ( Vertically opposite Angles )

∠ ECD = 70

In Triangle DCE,

∠ D + ∠C + ∠E = 180

30 + 70 + ∠E = 180

100 + ∠E = 180

∠ DEC = 180 - 100

∠ DEC = 80

Hope this helps you!