Complete the square for the given equation
x² - 2x + ____ + y² - 2y + _____ = 98
x² - 2x + (1) + y² - 2y + (1) = 98 + (1) + (1)
(x - 1)² + (x - 1)² = 100
(x - 1)² + (x - 1)² = 10²
Now the equation is in the form (x - h)² + (y - k)² = r²
Radius = 10
Supplementary Angles:

Arithmetically speaking, the closest 2 supplementary angles can get (in 3 and 2 digits respectively) is the upwritten.
Complementary Angles:

Simply, in this case, for angles to be numerically as close as possible - make both the angles 45°.