Answer:

Step-by-step explanation:
We want to write the trignometric expression:

As an algebraic equation.
First, we can focus on the inner expression. Let θ equal the expression:

Take the secant of both sides:

Since secant is the ratio of the hypotenuse side to the adjacent side, this means that the opposite side is:

By substitutition:

Using an double-angle identity:

We know that the opposite side is √(u² -100), the adjacent side is 10, and the hypotenuse is u. Therefore:

Simplify. Therefore:

By definition, two angles are supplementary if the sum of them is 180 degrees. In this case (see figure attached with the answer) the line AD is transversal to lines AB and DC. This is a proof of the Same-side interior angle theorem.
This theorem states that if we have two lines that are parallel and we intercept those two lines with a line that is transversal to both, same-side interior angles are formed, and also sum 180º, in other words, they are supplementary angles.
Then:
By the definition of a parallelogram, AB∥DC. AD is a transversal between these sides, so ∠A and ∠D are <em><u>same-side interior angles</u></em>. Because AB and DC are <em><u>parallel</u></em>, the same-side interior angles must be <em><u>supplementary</u></em> by the same-side interior angles theorem. Therefore, ∠A and ∠D are supplementary.
Answer:
C and E would be your Answer!
Answer:hope I ain’t latee
Step-by-step explanation: