Added surface area calculation for pyramid

Author: yrazvi32

src/main/java/com/thealgorithms/maths/Area.java

@@ -1,3 +1,4 @@
+
 package com.thealgorithms.maths;
 
 /**
@@ -69,30 +70,11 @@ public static double surfaceAreaSphere(final double radius) {
         return 4 * Math.PI * radius * radius;
     }
 
-    /**
-     * Calculate the surface area of a pyramid with a square base.
-     *
-     * @param sideLength side length of the square base
-     * @param slantHeight slant height of the pyramid
-     * @return surface area of the given pyramid
-     */
-    public static double surfaceAreaPyramid(final double sideLength, final double slantHeight) {
-        if (sideLength <= 0) {
-            throw new IllegalArgumentException("");
-        }
-        if (slantHeight <= 0) {
-            throw new IllegalArgumentException("slant height must be greater than 0");
-        }
-        double baseArea = sideLength * sideLength;
-        double lateralSurfaceArea = 2 * sideLength * slantHeight;
-        return baseArea + lateralSurfaceArea;
-    }
-
     /**
      * Calculate the area of a rectangle.
      *
      * @param length length of a rectangle
-     * @param width  width of a rectangle
+     * @param width width of a rectangle
      * @return area of given rectangle
      */
     public static double surfaceAreaRectangle(final double length, final double width) {
@@ -232,4 +214,23 @@ public static double surfaceAreaCone(final double radius, final double height) {
         }
         return Math.PI * radius * (radius + Math.pow(height * height + radius * radius, 0.5));
     }
+
+    /**
+     * Calculate the surface area of a pyramid with a square base.
+     *
+     * @param sideLength side length of the square base
+     * @param slantHeight slant height of the pyramid
+     * @return surface area of the given pyramid
+     */
+    public static double surfaceAreaPyramid(final double sideLength, final double slantHeight) {
+        if (sideLength <= 0) {
+            throw new IllegalArgumentException("Must be a positive sideLength");
+        }
+        if (slantHeight <= 0) {
+            throw new IllegalArgumentException("Must be a positive slantHeight");
+        }
+        double baseArea = sideLength * sideLength;
+        double lateralSurfaceArea = 2 * sideLength * slantHeight;
+        return baseArea + lateralSurfaceArea;
+    }
 }