Cameron wants to prove the Alternate Interior Angles Theorem. In the diagram, PQ∥RSComplete Cameron's proof that alternate interior angles ∠PVW and ∠VWS are congruent.Construct the midpoint M of WV, then rotate PQ,RS, and TU180∘ about M to get P′Q′,R′S′, and T′U′. Since M lies on ∠PVW1 and the rotation is ∠PVW2 coincides with ∠PVW3 are equidistant from M on ∠PVW1, so ∠PVW6 coincides with ∠PVW7 and ∠PVW8 coincides with ∠PVW3A ∠VWS0 rotation of a line is a parallel line, and the only line parallel to ∠VWS1 that passes through ∠PVW7 is ∠PVW3 Therefore, ∠PVW3 coincide, and ∠VWS5 and ∠VWS6 coincide. So, the rotation maps ∠PVW3Since rotation ∠PVW3 , ∠VWS9.
Q. Cameron wants to prove the Alternate Interior Angles Theorem. In the diagram, PQ∥RSComplete Cameron's proof that alternate interior angles ∠PVW and ∠VWS are congruent.Construct the midpoint M of WV, then rotate PQ,RS, and TU180∘ about M to get P′Q′,R′S′, and T′U′. Since M lies on ∠PVW1 and the rotation is ∠PVW2 coincides with ∠PVW3 are equidistant from M on ∠PVW1, so ∠PVW6 coincides with ∠PVW7 and ∠PVW8 coincides with ∠PVW3A ∠VWS0 rotation of a line is a parallel line, and the only line parallel to ∠VWS1 that passes through ∠PVW7 is ∠PVW3 Therefore, ∠PVW3 coincide, and ∠VWS5 and ∠VWS6 coincide. So, the rotation maps ∠PVW3Since rotation ∠PVW3 , ∠VWS9.
Construct Midpoint M: Construct the midpoint M of ar{WV}, then rotate PQightarrow, RSightarrow, and TUightarrow180ext@ about M.
Rotate Lines 180 Degrees: Since M is the midpoint of ar{WV} and the rotation is 180∘, ar{T'U'}^{\leftrightarrow} will coincide with ar{TU}^{\leftrightarrow}.
Coincidence of Points T and U: Points T and U are equidistant from M on TUh, so V′ coincides with W after the rotation.
Preservation of Vector Length and Orientation:V′W′ coincides with VW because a 180∘ rotation preserves the length and orientation of vectors.
Parallel Line to PQ: A 180∘ rotation of a line is a parallel line, and the only line parallel to PQ that passes through W is RS.
Coincidence of Points P′ and Q′: Therefore, P′′Q′′^{\leftrightarrow} must coincide with RS↔ after the rotation.
Preservation of Angles:V′P′ and WS coincide, meaning the rotation maps point P′ to point S and point Q′ to point R.
Preservation of Angles:V′P′ and WS coincide, meaning the rotation maps point P′ to point S and point Q′ to point R. Since rotation preserves angles, ∠PVW is congruent to ∠VWS because they are images of each other under the 180∘ rotation.
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