the marked angles are complementary → B
All 3 triangles are right with one angle = 90°
the sum of the angles in a triangle = 180°
thus the remaining 2 marked angles sum to 90°, thus are complementary
Every triangle has 180 degrees when you add there angles so you know that they will add up to 180
they are right triangles so the right angle has 90 degrees
so for the yellow triangle
90+45+x=180
135+x=180
45=x
we can tell where the purple and yellow triangle touch is 90 so 45+x=90 to find that angle which is 45
and the other one is 45
so there are two 90 degree angles and three 45 degree angles.
I hope that made sence
So, the negative would be divided out to make it 3, then square both sides to get rid of the square root and get 9, then subtract 15 and you get -6. <span />
