Answer:
69.5 if C and D both add up to 90, M=90 if both angles C and D were complementary to combine to a supplementary.
Explanation:
You're trying to find m which is a variable for measurement for the "D" angle.
Info Given:
20.5 for angle C
Unknown for angle D
Both angles are Complementary.
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I have 2 answers for this (The question was stated unclearly so I have 2 interpretations of this)
1st Answer:
If you're asking to solve for M but the C and D angles add up to 90 then do
90 - 20.5 = 69.5
2nd Answer:
We know that both angles are complementary which are 90-degree angles.
If we combine them then the angles add up to 180.
So C and D add up to form a Supplementary Angle.
20.5+69.5 + m = 180
Then M could possibly be 90.