Answer:
C2- 65° C3- 84°
Explanation:
for C2:
the 2 parallel lines and the one cutting fully through form a transversal.
One of the rules for this is that co-interior angles (the 2 on the same side of the intersecting line) add to 180°.
This means that the angle at the top left (still within the triangle) should be 50° (180-121).
The other angle within the triangle (not the x one) is vertically opposite (opposite or "diagonal") with the 65°.
Vertically opposite angles have the same value, meaning the second angle is 65°.
In a triangle, the 3 angles add to 180. In this case, 50+65+x=180, which can be simplified to 115+x=180. Subtracting 115 from both sides gives x=65°.
For C3-
Imagine a parallel line is going through the angle x, splitting it into 2 angles (let's call them a and b).
With a being the top half, you can use the 133° given to help you. Like before, vertically opposite angles are the same, so the value "diagonal" to 133° should also be 133°. Using the co-interior rule, a should be 180-133, which gives 47°.
For b, we can skip this first step entirely. Since 143 and b are co-interior, 180-143=b, therefore b=37°.
To use these, remember a+b=x, which by subbing in the values gives 47+37=x, simplified to x=84°.
** I suggest revising the types of transversal relationships (corresponding, alternate, vertically opposite and co-interior). It's difficult explaining this without diagrams, but if you need more clarification, I'm happy to help!