hello i just need help with this question please and thank you
stay safe from corona:)

Answer:
hope you're doing well today!,
Step-by-step explanation:
<2 + <3 = <1. it doesn't say if <1 is also 90º but you know it will be because the measure of a line if 180º so just add and subtract, you'll see that <1 is 90º.
also <5 = <3 because of vertical angles.
<6+<7 = 180º (straight line definition)
<9 = <11, < 8 = <10 both vertical angles
hope this helps, ask if you need additional help!!