Is this question valid? If $\angle A$ and $\angle B$ are complements, and the supplement of $\angle B$ is $78^\circ$, then find $\angle A$.

Question

Question: Angle A and B are complementary. If the supplement of angle B is 78°. What is the measure of angle A?

I am confused since

• A + B = 90
• B + 78 = 180
• B = 102
• A + 102 = 90
• A = -12

I think the question should be the supplement of angle B is 102°.

Is the question right or wrong?

Answer 1

Yes indeed we have that

• $A+B=90°$

• $B+78=180° \implies B=102°$

then $A=-12°=348°$.

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Edit

In the context of oriented angles, the result could be correct since it is fine to have negative values too for angles.

Otherwise there could be an error or a typo in the formulation of the problem.