Which pairs of non-overlapping angles share a ray to make a right angle?

In the diagram of circle o, what is the measure of zabc?

Parallelogram efgh is a rectangle. he = 6, and fe = 8. find ge: and find fj:

Consider u = {x|x is a negative real number}which is an empty set? o {x|x eu and x has a negative cube root}o {x|x eu and x has a negative square root}{x|x eu and x is equal to the product of a positive number and -1}{x|x eu and x is equal to the sum of one negative and one positive number?