diff --git a/documentation/cos.md b/documentation/cos.md
index 2238b42..56ee012 100644
--- a/documentation/cos.md
+++ b/documentation/cos.md
@@ -22,7 +22,7 @@ A BigArith object with its value equals to the cosine of the given angle.
 ### Description
 There is no method function for `cos()` so it should ALWAYS be used as a static member function `BigArith.cos()`.
 
-The returned result is the cosine of the angle (given in degress) to 200 decimal places. 
+The returned result is the cosine of the angle (given in degrees) to 200 decimal places. 
 
 
 ### Examples
diff --git a/documentation/list_constants.md b/documentation/list_constants.md
index 1075884..90e67ad 100644
--- a/documentation/list_constants.md
+++ b/documentation/list_constants.md
@@ -7,8 +7,7 @@ Here is a updated list of constants predefined in BigArith.js
 	<col style="width:40%; word-wrap:break-word;">
 	<thead><tr><td>Constant</td><td>Description</td><td style="width:130px">Value (to 200 decimal places)</td><td>Usage</td></tr></thead>
 	<tbody>
-		<tr><td>PI</td> <td>pi</td> <td>3.1415926535897932384...196</td><td>var ba = new BigArith("PI");</td></tr>
-
+		<tr><td>PI</td> <td>pi</td> <td>3.14159265358979323846...196</td><td>var ba = new BigArith("PI");</td></tr>
 		<!-- -------------------------------------------------------------------------------------------
 		<tr><td>LN2</td> <td>ln(2)</td> <td>0.6931471805599453</td><td>var ba = new BigArith("LN2");</td></tr>
 
diff --git a/documentation/sin.md b/documentation/sin.md
index 24dc622..1578ec7 100644
--- a/documentation/sin.md
+++ b/documentation/sin.md
@@ -22,7 +22,7 @@ A BigArith object with its value equals to the sine of the given angle.
 ### Description
 There is no method function for `sin()` so it should ALWAYS be used as a static member function `BigArith.sin()`.
 
-The returned result is the sine of the angle (given in degress) to 200 decimal places. 
+The returned result is the sine of the angle (given in degrees) to 200 decimal places. 
 
 
 ### Examples
diff --git a/documentation/tan.md b/documentation/tan.md
index 5121c02..3e3dd7b 100644
--- a/documentation/tan.md
+++ b/documentation/tan.md
@@ -1,6 +1,6 @@
 # tan() [UNSTABLE]
 
-> This function is still unstable and in the developmental stage. It takes about `computation time for sin + computation time for cos` milliseconds to compute tan &theta;&deg;.
+> This function is still unstable and in the developmental stage. It takes about `computation time for sin + computation time for cos` milliseconds to compute tan &theta;&deg; (which is about  for tan 90&deg;).
 
 `tan()` returns the tangent of an angle (given in degrees). This has only a static method function.
 
@@ -22,7 +22,7 @@ A BigArith object with its value equals to the tangent of the given angle.
 ### Description
 There is no method function for `tan()` so it should ALWAYS be used as a static member function `BigArith.tan()`.
 
-The returned result is the tangent of the angle (given in degress) to 200 decimal places. 
+The returned result is the tangent of the angle (given in degrees) to 200 decimal places. 
 
 
 ### Examples