Answer:
4x+10=90
X=20
Explanation:
Quick hint, if the triangle starts from the middle of the circle, you have a 90 degree triangle. Which means the point is also known (equals) as 90 degree so:
4x+10=90
This is now an equation, what's left is to solve for x
4x+10=90
Collect like tterms
4x= 90-10
4x=80
Now we have to leave x alone by dividing both sides by what is clinging to x
4x/4=80/4
X= 20