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Is it true that in space, angles with correspondingly perpendicular sides are equal or sum up to $180^{\circ}$?
Consider the cube $A B C D A 1 B 1 C 1 D 1(A A 1\|B B 1\| C C 1 \| D D 1)$ and the angles $B A D$ and $A 1 A B 1$. Since the line $A D$ is perpendicular to the plane $A A 1 B 1 B, A D \perp A B 1$. Therefore, $B A D$ and $A 1 A B 1$ are angles with respectively perpendicular sides. At the same time, $\angle B A D=90^{\circ}$, while $\angle A 1 A B 1=45^{\circ}$.

## Answer

No.

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