Oblique Sketches of 3D Shapes

An Oblique Sketch is a method of representing a three-dimensional (3D) object on a two-dimensional (2D) surface (like paper) to create the illusion of depth.

Analogy: Imagine drawing a box on a whiteboard. YWe can’t draw the actual depth, so you draw diagonal lines to trick the eye into seeing the 3D shape.

Purpose: Helps visualize and represent 3D solids easily on paper, useful in geometry and design.

• Step 1: Draw the Front Rectangle

• Step 2: Draw the Back Rectangle

• Step 3: Draw Receding Edges

• Step 4: Complete the Figure

• Step 5: Apply Hidden Edge Convention

Step 1:
Take a square (graph) paper.

Step 2:
Draw the front face as a square of side 4 cm.

Step 3:
Draw another square (same size) slightly behind and above the first one — this represents the back face.

Step 4:
Join the corresponding corners of both squares.

Step 5:
Show hidden edges (the parts not directly visible) using dotted lines.

1. Architecture and Building Design

Architects use oblique sketches to visualize building layouts

2. Engineering and Machinery

Engineers draw machine parts and assemblies using oblique sketches

3. Education and Learning

Students use oblique sketches in mathematics and geometry assignments

• An oblique sketch represents 3D solids on a 2D surface.

• The front face is drawn accurately, while the side faces are inclined to show depth.

• Hidden edges are always drawn using dotted lines.

• he depth edges are drawn at an angle (usually 45°) and are often shorter than actual size to show perspective.