Check if a point lies between 2 points (#15554)

Co-authored-by: rajatgarg <rajatgarg@adobe.com>

core-java-modules/core-java-lang-math-3/src/main/java/com/baeldung/math/pointbetweentwopoints/PointLiesBetweenTwoPoints.java

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+package com.baeldung.math.pointbetweentwopoints;
+
+public class PointLiesBetweenTwoPoints {
+    public static boolean findUsingDistanceFormula(double x1, double y1, double x2, double y2, double x, double y) {
+        double distanceAC = Math.sqrt(Math.pow(x - x1, 2) + Math.pow(y - y1, 2));
+        double distanceCB = Math.sqrt(Math.pow(x2 - x, 2) + Math.pow(y2 - y, 2));
+        double distanceAB = Math.sqrt(Math.pow(x2 - x1, 2) + Math.pow(y2 - y1, 2));
+        return Math.abs(distanceAC + distanceCB - distanceAB) < 1e-9;
+    }
+
+    public static boolean findUsingSlopeFormula(double x1, double y1, double x2, double y2, double x, double y) {
+        double slopeAB = (y2 - y1) / (x2 - x1);
+        double slopeAC = (y - y1) / (x - x1);
+        return slopeAB == slopeAC && ((x1 <= x && x <= x2) || (x2 <= x && x <= x1)) && ((y1 <= y && y <= y2) || (y2 <= y && y <= y1));
+    }
+}

core-java-modules/core-java-lang-math-3/src/test/java/com/baeldung/math/pointbetweentwopoints/PointLiesBetweenTwoPointsUnitTest.java

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+package com.baeldung.math.pointbetweentwopoints;
+
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class PointLiesBetweenTwoPointsUnitTest {
+
+    @Test
+    public void givenAPoint_whenUsingDistanceFormula_thenCheckItLiesBetweenTwoPoints() {
+        double x1 = 1, y1 = 1;
+        double x2 = 5, y2 = 5;
+        double x = 3, y = 3;
+        assertTrue(PointLiesBetweenTwoPoints.findUsingDistanceFormula(x1, y1, x2, y2, x, y));
+    }
+
+    @Test
+    public void givenAPoint_whenUsingSlopeFormula_thenCheckItLiesBetweenTwoPoints() {
+        double x1 = 1, y1 = 1;
+        double x2 = 5, y2 = 5;
+        double x = 3, y = 3;
+        assertTrue(PointLiesBetweenTwoPoints.findUsingSlopeFormula(x1, y1, x2, y2, x, y));
+    }
+}