#### You can enter input as either a decimal or as the adjacent over the hypotenuse

There are 2 different ways that you can enter input into our arc cos calculator.

**Method 1: Decimal**

Enter a decimal between -1 and 1 inclusive. Remember that you cannot have a number greater than 1 or less than -1.

**Method 2: Adjacent / Hypotenuse**

Entering the ratio of the adjacent side divided by the hypotenuse. (review inverse cosine here)