1. i think Choice A.(Unsure of this one, it’s between choices A & C)
2. t=19
3. I think Choice C
I believe the answer is (4.2)(10⁻⁵)
Using our congruency statement <span>DEFGH ≅ QRSTU, we can see which angles map onto each other.
</span>D ≅ Q
E ≅ R
F ≅ S
G ≅ T
H ≅ U
We see that E ≅ R, and since E is 143 degrees, R = 143 degrees.
Why is this true, you may ask? When dealing with congruency, the given points/letters (they are really both) are congruent to the corresponding shapes letter/point. For example, if triangle ABC ≅ DEF, A would correspond to D, B would correspond to E, etc. When you see these types of problems, congruency will be applied to angles (it could apply to lines in other cases).
If you have any questions, feel free to ask!
:)