Answer:
As per the properties of parallel lines and interior alternate angles postulate, we can prove that:
![m\angle 5+m\angle 2+m\angle 6=180^\circ](https://img.qammunity.org/2021/formulas/mathematics/college/uzsewo0qpycgki5z89e1xy4a5yig196ojo.png)
Explanation:
Given:
Line y || z
i.e. y is parallel to z.
To Prove:
![m\angle 5+m\angle 2+m\angle 6=180^\circ](https://img.qammunity.org/2021/formulas/mathematics/college/uzsewo0qpycgki5z89e1xy4a5yig196ojo.png)
Solution:
It is given that the lines y and z are parallel to each other.
are interior alternate angles because lines y and z are parallel and one line AC cuts them.
So,
..... (1)
Similarly,
are interior alternate angles because lines y and z are parallel and one line AB cuts them.
So,
...... (2)
Now, we know that the line y is a straight line and A is one point on it.
Sum of all the angles on one side of a line on a point is always equal to
.
i.e.
![m\angle 1+m\angle 2+m\angle 3=180^\circ](https://img.qammunity.org/2021/formulas/mathematics/college/za3joj5nrze3lka7f488i1gikskscym3yv.png)
Using equations (1) and (2):
We can see that:
![m\angle 5+m\angle 2+m\angle 6=180^\circ](https://img.qammunity.org/2021/formulas/mathematics/college/uzsewo0qpycgki5z89e1xy4a5yig196ojo.png)
Hence proved.