How to Draw an Impossible Triangle: Easy 10-Step Optical Illusion

Ready to trick your eyes? This classic Penrose triangle is a fantastic way for artists ages 8+ to practice parallel lines and 3D perspective. You only need a pencil, a ruler for crisp edges, and an eraser to create this mind-bending optical illusion.

10 Steps

🎯 Final Result

A finished, shaded impossible triangle drawing on a clean background.

Step-by-Step Instructions

Step 1: Sketch the Inner Triangle

A small, perfectly equilateral triangle drawn in the center of a white background.

Draw a small, equilateral triangle in the center of your page. Teacher's Tip: Use a ruler to ensure all three sides are equal, as this forms the 'hole' of your illusion.

Step 2: Extend the Corner Guides

The central triangle with three short diagonal lines extending outward from each vertex.

Extend a short, straight line diagonally outward from each of the three points. Tip: Keep these lines light; they act as the scaffolding for your 3D structure.

Step 3: Build the First Side

Two new lines added to the top and right side of the central triangle, forming the start of a 3D bar.

From the top diagonal line, draw a line parallel to the side of your inner triangle. Then, draw a second line parallel to the bottom side. Tip: Precision is key here—use your ruler to keep the lines perfectly parallel.

Step 4: Establish the Base

A horizontal line added to the bottom, creating the base of the triangle's structure.

Draw a horizontal line from the lowest diagonal. Ensure it is equidistant from the other lines to maintain the illusion of depth.

Step 5: Extend the Left Side

A vertical line added to the left side, extending the geometric shape.

Draw a long line upward from the remaining diagonal, keeping it parallel to the inner triangle's side. Tip: Think of this as building the outer wall of a box.

Step 6: Connect the Top Corner

A long diagonal line connecting the top sections to continue the illusion.

From the top of your last line, draw a long line parallel to the opposite side of the triangle. You are now closing the loop of the shape.

Step 7: Add the Final Vertical

A vertical line added to the middle section, further defining the 3D structure.

Extend a line upward from the middle horizontal section. This creates the final 'impossible' overlap.

Step 8: Close the First Corner

A small line segment closing one of the three corners of the triangle.

Connect the lines to close one of the corners. Tip: Use short, clean strokes to ensure the corners look sharp and intentional.

Step 9: Finalize the Outline

The completed outline of the impossible triangle with all corners closed.

Close the remaining two corners with short, straight lines. Your impossible triangle is now complete! Erase any stray guide lines to make it pop.

Step 10: Add Color and Depth

The finished impossible triangle with shading applied to create a 3D effect.

Add shading to the inner faces to enhance the 3D effect. Tip: Use a darker shade on the 'shadowed' sides to make the triangle look like it's popping off the page!