diff --git a/src/3000-maximum-area-of-longest-diagonal-rectangle/main.go b/src/3000-maximum-area-of-longest-diagonal-rectangle/main.go
new file mode 100644
index 0000000..1deb223
--- /dev/null
+++ b/src/3000-maximum-area-of-longest-diagonal-rectangle/main.go
@@ -0,0 +1,28 @@
+package main
+
+import (
+	"math"
+)
+
+func areaOfMaxDiagonal(dimensions [][]int) int {
+	var area int
+	var maxArea int
+	var diagonal float64
+	var maxDiagonal float64
+	for i := range dimensions {
+		length := dimensions[i][0]
+		width := dimensions[i][1]
+		diagonal = math.Sqrt(float64(length)*float64(length) + float64(width)*float64(width))
+		area = length * width
+		if diagonal > maxDiagonal {
+			maxDiagonal = diagonal
+			maxArea = area
+		}
+		if diagonal == maxDiagonal {
+			if area > maxArea {
+				maxArea = area
+			}
+		}
+	}
+	return maxArea
+}
diff --git a/src/3000-maximum-area-of-longest-diagonal-rectangle/main_test.go b/src/3000-maximum-area-of-longest-diagonal-rectangle/main_test.go
new file mode 100644
index 0000000..1ace576
--- /dev/null
+++ b/src/3000-maximum-area-of-longest-diagonal-rectangle/main_test.go
@@ -0,0 +1,53 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/arunsathiya/leetcode/testutil"
+)
+
+func TestAreaOfMaxDiagonal(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		expected int
+	}{
+		{
+			name:     "first test case from leetcode",
+			input:    "[[9,3],[8,6]]",
+			expected: 48,
+		},
+		{
+			name:     "second test case from leetcode",
+			input:    "[[3,4],[4,3]]",
+			expected: 12,
+		},
+		{
+			name:     "third test case from leetcode",
+			input:    "[[6,5],[8,6],[2,10],[8,1],[9,2],[3,5],[3,5]]",
+			expected: 20,
+		},
+		{
+			name:     "fourth test case from leetcode",
+			input:    "[[4,7],[8,9],[5,3],[6,10],[2,9],[3,10],[2,2],[5,8],[5,10],[5,6],[8,9],[10,7],[8,9],[3,7],[2,6],[5,1],[7,4],[1,10],[1,7],[6,9],[3,3],[4,6],[8,2],[10,6],[7,9],[9,2],[1,2],[3,8],[10,2],[4,1],[9,7],[10,3],[6,9],[9,8],[7,7],[5,7],[5,4],[6,5],[1,8],[2,3],[7,10],[3,9],[5,7],[2,4],[5,6],[9,5],[8,8],[8,10],[6,8],[5,1],[10,8],[7,4],[2,1],[2,7],[10,3],[2,5],[7,6],[10,5],[10,9],[5,7],[10,6],[4,3],[10,4],[1,5],[8,9],[3,1],[2,5],[9,10],[6,6],[5,10],[10,2],[6,10],[1,1],[8,6],[1,7],[6,3],[9,3],[1,4],[1,1],[10,4],[7,9],[4,5],[2,8],[7,9],[7,3],[4,9],[2,8],[4,6],[9,1],[8,4],[2,4],[7,8],[3,5],[7,6],[8,6],[4,7],[25,60],[39,52],[16,63],[33,56]]",
+			expected: 2028,
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			dimensions := testutil.Parse2DIntArray(test.input)
+			output := areaOfMaxDiagonal(dimensions)
+			if output != test.expected {
+				t.Errorf("Expected %d, got %d", test.expected, output)
+			}
+		})
+	}
+}
+
+func BenchmarkAreaOfMaxDiagonal(b *testing.B) {
+	// TODO: add benchmark inputs
+	for i := 0; i < b.N; i++ {
+		// areaOfMaxDiagonal(...)
+	}
+}
diff --git a/testutil/leetcode.go b/testutil/leetcode.go
new file mode 100644
index 0000000..7cb28c2
--- /dev/null
+++ b/testutil/leetcode.go
@@ -0,0 +1,16 @@
+package testutil
+
+import (
+	"encoding/json"
+)
+
+// Parse2DIntArray converts LeetCode format string to [][]int
+// Example: "[[1,2],[3,4]]" -> [][]int{{1,2},{3,4}}
+func Parse2DIntArray(jsonStr string) [][]int {
+	var result [][]int
+	err := json.Unmarshal([]byte(jsonStr), &result)
+	if err != nil {
+		panic("Failed to parse 2D int array: " + err.Error())
+	}
+	return result
+}