Answer:
Step-by-step explanation:
The given postulate If two lines intersect, then they intersect in exactly one point is true because whenever the two lines intersect they intersect at one point only and we know that a postulate is a statement that we accept without proof.
The given theorem If two distinct planes intersect, then they intersect in exactly one line is true as theorem is a statement that has been proved and it has been proved that if two distinct planes intersect, then they intersect in exactly one line.
The figures are drawn to prove them.
Answer:

Step-by-step explanation:
The given trigonometric equation is
for
.
We divide through by 5 to get;
We take the inverse tangent of both sides to obtain;
Since the tangent ratio is positive, it means
could also be in the 3rd quadrant. But this is outside the given range.
Therefore the correct answer is A