Answer:
9b) -8 = y
9a) 72° = m∠ABC
Explanation:
Since you have an angle trisector, in this case, m∠CBE ≅ m∠DBA, therefore you set x equal to 8, plus, according to Morley's Trisector Theorem, all three angles form an equilateral triangle, so m∠BOC also has to equal 24°:
![{8}^(2) - 5(8) = 64 - 40 = 24 \\ \\ 6(8) - 24 = 48 - 24 = 24 \\ \\ 2(8) - y = 24 >> 16 - y = 24 >> -8 = y](https://img.qammunity.org/2020/formulas/mathematics/middle-school/dmjm3zqk6lsaw9vjuazx148dkzm6okso90.png)
Then, m∠ABC comes from multiplying 3 by 24 [three twenty-four's], which results in 72°.
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