Issue TheAlgorithms#5479 resolved, Algorithm Frustum of Cone and tested it

Author: Anurag

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

@@ -90,4 +90,9 @@ public static double volumePrism(double baseArea, double height) {
     public static double volumePyramid(double baseArea, double height) {
         return (baseArea * height) / 3;
     }
+
+
+    public static double volumeFrustumOfCone(double r1, double r2, double height){
+        return (Math.PI * height / 3) * (r1 * r1 + r2 * r2 + r1 * r2);
+    }
 }

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

@@ -0,0 +1,27 @@
+package com.thealgorithms.maths;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertTrue;
+
+public class VolumeTest {
+
+    @Test
+    public void volume(){
+
+//        test cube
+        assertTrue(Volume.volumeCube(7) == 343.0);
+        assertTrue(Volume.volumeCuboid(2, 5, 7) == 70.0);
+        assertTrue(Volume.volumeSphere(7) == 1436.7550402417319);
+        assertTrue(Volume.volumeCylinder(3, 7) == 197.92033717615698);
+        assertTrue(Volume.volumeHemisphere(7) == 718.3775201208659);
+        assertTrue(Volume.volumeCone(3, 7) == 65.97344572538566);
+        assertTrue(Volume.volumePrism(10, 2) == 20.0);
+        assertTrue(Volume.volumePyramid(10, 3) == 10.0);
+        assertTrue(Volume.volumeFrustumOfCone(3, 5, 7) == 359.188760060433);
+
+
+
+    }
+
+}