Vertical Angles: Theorem and Proof
Theorem: In a pair of intersecting lines the vertically opposite angles are equal. It can be seen that ray \overline{OA} stands on the line \overleftrightarrow{CD} and according to Linear Pair Axiom, if a ray stands on a line, then the adjacent angles form a linear pair of angles.
<u>Given</u>:
Line m is parallel to line n.
The measure of ∠1 is (4x + 15)°
The measure of ∠2 is (9x + 35)°
We need to determine the measure of ∠1
<u>Value of x:</u>
From the figure, it is obvious that ∠1 and ∠2 are linear pairs.
Thus, we have;

Substituting the measures of ∠1 and ∠2, we get;




Thus, the value of x is 10.
<u>Measure of ∠1:</u>
The measure of ∠1 can be determined by substituting x = 10 in the measure of ∠1
Thus, we have;



Thus, the measure of ∠1 is 55°
Answer:
c
Step-by-step explanation:
the normal equation is 120 and c is 120
X = 4 and Y = 9. I did a complicated way of doing it so if u copy it it would look weird
A square, rectangle, rhombus (I think)