Tentukan sama ada garis PQ dan RS adalah selari atau tidak. Nyatakan sebab anda. Determine whether the lines PQ and RS are parallel or not. State your reason.

The two angles given are corresponding angles.
Angle 1 = $45^\circ$
Angle 2 = $45^\circ$

For lines to be parallel, corresponding angles must be equal.
Since $45^\circ = 45^\circ$, the corresponding angles are equal.

Lines PQ and RS are parallel because their corresponding angles are equal.

2)

The two angles given are alternate exterior angles.
Angle 1 = $75^\circ$
Angle 2 = $75^\circ$

For lines to be parallel, alternate exterior angles must be equal.
Since $75^\circ = 75^\circ$, the alternate exterior angles are equal.

Lines PQ and RS are parallel because their alternate exterior angles are equal.

3)

The two angles given are alternate interior angles.
Angle 1 = $91^\circ$
Angle 2 = $91^\circ$

For lines to be parallel, alternate interior angles must be equal.
Since $91^\circ = 91^\circ$, the alternate interior angles are equal.

Lines PQ and RS are parallel because their alternate interior angles are equal.

4)

The two angles given are alternate exterior angles.
Angle 1 = $130^\circ$
Angle 2 = $130^\circ$

For lines to be parallel, alternate exterior angles must be equal.
Since $130^\circ = 130^\circ$, the alternate exterior angles are equal.

Lines PQ and RS are parallel because their alternate exterior angles are equal.

5)

The two angles given are consecutive interior angles (also known as interior angles on the same side of the transversal).
Angle 1 = $105^\circ$
Angle 2 = $125^\circ$

For lines to be parallel, consecutive interior angles must sum to $180^\circ$.
Sum = $105^\circ + 125^\circ = 230^\circ$.
Since $230^\circ \neq 180^\circ$, the sum is not $180^\circ$.

Lines PQ and RS are not parallel because their consecutive interior angles do not sum to $180^\circ$.

6)

The two angles given are consecutive interior angles.
Angle 1 = $63^\circ$
Angle 2 = $115^\circ$

For lines to be parallel, consecutive interior angles must sum to $180^\circ$.
Sum = $63^\circ + 115^\circ = 178^\circ$.
Since $178^\circ \neq 180^\circ$, the sum is not $180^\circ$.

Lines PQ and RS are not parallel because their consecutive interior angles do not sum to $180^\circ$.