Please help me :(, I want to understand how to prove it

We know that angels 5 and 6 are vertical angles, and that vertical angles are equal. We also know that angles 7 is equal to angle 6, in turn meaning that angle 7 is also equal to angle 5. Now we look at angle 8. We can see that angle 8 is vertical to angle 7, meaning its also equal to angle 7. We already established before that angle 7 is equal to angle 5, so if angle 8 is equal to angle 7 which is equal to angle 5. Then angle 8 is equal to angle 5.

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step-by-step explanation: