90°is the answer because 90°+90°=180°
Answer:

Step-by-step explanation:
Write down the problem;

Simplify

Convert so that the fractions have a common denominator; multiply the numerator and denominator of both fractions such that the denominators are equal;

Add the fractions;

Convert to mixed number;

Answer: 21
Step-by-step explanation:
252 = 2^2*3^2*7
√252 = 6√7