Answer:
So, Plane ABC and plane BCE _may_ be the same plane.
Step-by-step explanation:
This happens when E is on Plane ABC (or you could say, A is on Plane BCE). If not, then they are two different planes.
Answer:
Complementary angles.
Step-by-step explanation:
Notice that
and
, by given.
, by sum of angles.
, by supplementary angles definition.

Which means,

Therefore,
, in other words, angles a and b are complementary by definition.
Find a number you can multiply by the bottom of the fraction to make it 10, or 100, or 1000, or any 1 followed by 0s.
Multiply both top and bottom by that number.
Then write down just the top number, putting the decimal point in the correct spot (one space from the right hand side for every zero in the bottom number)