Question: Is it possible to change a setting, property, etc in Swift for iOS so that it assumes degrees for trigonometry calculations rather than radians?

For example `sin(90)` would be evaluated to `1`.

I have:

```
let pi = 3.14 
var r2d = 180.0/pi
var d2r = pi/180

```

... but the conversions are getting really involved for some of the long trig equations.

Answer: 
Adding an extension to identify the kind of value clearly would be a appropriate way to handle such a thing:

```
import Darwin // needed to get M_PI
extension Double {
  public var degrees: Double { return self * M_PI / 180 }
  public var ㎭: Double { return self * 180 / M_PI }
}

```

Pop that into a playground and see how you get the results you expect:

```
sin(90.degrees)  --> 1.0
1.㎭  -->  57.2957795130823
1.㎭.degrees --> 1.0
(M_PI / 3).㎭  -->  60.0

```
There's no setting or property to change the built-in trigonometric functions. You should just work strictly in radians if you want to simplify your expressions, or define your own `sindeg`, `cosdeg`, etc.

Each of the floating-point types has a built-in `static` member named `pi` whose value is the best approximation to π. For example: `Double.pi`, `Float.pi`, `CGFloat.pi`.

Also, sin 90˚ is 1, not 0.