Declaring a property with the val keyword instead of var makes it a read-only property. That means we can only get the property.

What's wrong with this code?

We can't set a property declared with valThe Triangle class isn't named properlytotalDegrees isn't a property of the Triangle class

Nice! Since a triangle's angle is always 180, declaring the totalDegrees property with val keeps us from changing its value.

Whoops! Might it have to do with the property declared using the val keyword?