Fix pyramid slant height error message

Author: Axsasf

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

@@ -77,12 +77,12 @@ public static double surfaceAreaSphere(final double radius) {
      * @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("slant height must be greater than 0");
-        }
+       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;