m ∠b = 133°, m ∠c = 47°, and m ∠d = 133°.
<h3>
Further explanation</h3>
Follow the attached picture. I sincerely hope that's precisely a correct illustration.
We will use a graph of two intersecting straight lines.
Note that m ∠a and m ∠c are vertical angles. Since vertical angles share the same measures, in other words always congruent, we see 
We continue to determine m ∠b and m ∠d.
Note that m ∠b and m ∠d represent supplementary angles. Recall that supplementary angles add up to 180°.
Let us see the following steps.


Both sides subtracted by 47°.

Thus 
Finally, note that m ∠b and m ∠d are vertical angles. Accordingly, 
<u>Conclusion:</u>
- m ∠a = 47°
- m ∠b = 133°
- m ∠c = 47°
- m ∠d = 133°
<u>Notes:</u>
- Supplementary angles are two angles when they add up to 180°.

- Vertical angles are the angles opposite each other when two lines cross. Note that vertical angles are always congruent, or of equal measure.

<h3>Learn more</h3>
- About the measure of the central angle brainly.com/question/2115496
- Undefined terms needed to define angles brainly.com/question/3717797
- Find out the measures of the two angles in a right triangle brainly.com/question/4302397
Keywords: m∠a = 47°, m∠b, m∠c, and m∠d, 133°, vertical angles, supplementary, 180°, congruent
Answer: d
Step-by-step explanation:
The probability of not being purple is the probability of the three other colors. Suppose the number of purple marbles is x. Then we have 20+30+40+x = 90 + x marbles. Then the probability of not being purple is 90/(90+x). If this fraction can have a lowest term for some value of x, then the numerator of this lowest term must be a factor of 90.
Checking through the options, only option D has a non-factor of 90 as its numerator.
A because 2x9 equals 18 and 9x2 equals 18