What’s -) how would you solve this equation

-21

Step-by-step explanation:

When dealing with negatives and subtracting you are basically adding them together

11

Step-by-step explanation:

the 2 negatives "fuse together"as in it becomes a + this is always the case if you are subtracting anything by a negative number. so now your left with -5 + 16. which equals your awnser 11.

The triangle with the right angle and 45 degree measure has angles of 90, 45, and 45. Since this is a reflection, the triangle will have the same values, with 'a' being equal to 45 degrees.
The right angle technically makes a linear pair as well, allowing you to identify the equivalence of the triangles.