Question

Problem

Answer 1

Answer:

Complementary angles.

Step-by-step explanation:

The graph is attached.

Notice that $\angle a=\angle AXY$, $\angle b = \angle YXB$ and $\angle BXC = 90\°$, by given.

$\angle AXB = \angle AXY + \angle YXB$, by sum of angles.

$\angle AXB + \angle BXC = 180\°$, by supplementary angles definition.

$\angle AXB + 90\° = 180\°\\\angle AXB = 180\° - 90\°\\\angle AXB = 90\°$

Which means,

$\angle AXB = \angle AXY + \angle YXB = 90\°$

Therefore, $\angle a + \angle b = 90\°$, in other words, angles a and b are complementary by defintion.

So, the right answer is the second choice.