I need help for #9 please help I got math class in 30 minutes :))!! Thank u

In questions it's given that ∠B = 85°, which is an error and correct answer is ∠B = 95°.

Step-by-step explanation:

We know that sum of alternate angles in a parallelogram is 180°. Using this property, we will solve the question! We have a parallelogram inscribed in a circle with measure of angles as  ∠A=100° and ∠D=85°. Now, according to property : ∠A + ∠C = 180° and ∠D + ∠B = 180°.

Let's consider for ∠D + ∠B = 180°:

⇒ 85° + ∠B = 180°

⇒∠B =  180° - 85°

⇒∠B = 95°

Also, for ∠A + ∠C = 180°:

⇒ 100° + ∠C = 180°

⇒∠C =  180° - 100°

⇒∠C = 80°

In questions it's given that ∠B = 85°, which is an error and correct answer is ∠B = 95°.

ratio is 2 : 9

the answer is three

13.5 : 3