import 'package:flutter/material.dart'; void main() => runApp(MyApp()); class MyApp extends StatelessWidget { @override Widget build(BuildContext context) { return MaterialApp( home: Scaffold( appBar: AppBar( title: Text('Triangle Container'), ), body: Center( child: TriangleContainer(), ), ), ); } } class TriangleContainer extends StatelessWidget { @override Widget build(BuildContext context) { return Container( width: 200, height: 200, decoration: ShapeDecoration( color: Colors.blue, shape: CustomPainterShape(), ), ); } } class CustomPainterShape extends CustomPainter { @override void paint(Canvas canvas, Size size) { final paint = Paint()..color = Colors.blue; final path = Path() ..moveTo(size.width / 2, 0) // Top-center point ..lineTo(size.width, size.height) // Bottom-right point ..lineTo(0, size.height) // Bottom-left point ..close(); // Close the path to form a triangle canvas.drawPath(path, paint); } @override bool shouldRepaint(CustomPainter oldDelegate) { return false; } }