Answer:
+89
Step-by-step explanation:
Square when you look at the graphed answer
Supplementary angles are those which sum upto 180°

Complementary are those which sum to 90°

so if you know one angle, you can find other.
36 total children
Ratio of boys to girls is: 3:1
36/4 = 9 9 children to each part of the ratio
9 x 3 = 27 total boys
9 x 1 = 9 total girls