I need help what does x equal

x = 53°

Step-by-step explanation:

Before the river gets divided into two different degrees its a straight angle.

If you add x° to (2x + 21)° it should equal 180°

Now you set it up to solve for x

x° + (2x + 21)° = 180°

Add the x's together

3x° + 21° = 180°

Then subtract 21° from 180°

3x° = 159°

Then divide both sides by 3 to get x

x = 53°

i belive those are the ones that are under 90 degreese.