Question

angles and lines end - of - lesson test
5 to install baseboards in a 90 degree corner of a room, the boards must be cut to meet in a complementary angle. if one is cut at 45 degrees, what angle does the other need to be cut at?
60 degrees
50 degrees
30 degrees
45 degrees
skip 4/10 complete

Explanation:

Step1: Recall complementary - angle definition

Complementary angles add up to 90 degrees.
Let the two angles be $x$ and $y$, so $x + y=90^{\circ}$.

Step2: Substitute the given angle

Given $x = 45^{\circ}$, then $y=90^{\circ}-x$.
$y = 90 - 45=45^{\circ}$

Answer:

D. 45 degrees