MechSimulator

Protractor Simulator

Interactive angle measurement trainer — LC = 1°

Mode
Precision (LC)
Drag to rotate arm  |  ←→ Arrow keys
Angle
0
°
ANGLE
0
deg
Scale Reading
ALT
180
deg
Other Scale
TYPE
Zero
 
Angle Class
READING & CLASSIFICATION
ANGLE: inner scale reading  ·  ALT: outer scale (180° − ANGLE)  ·  LC = 1°
ANGLE = 0°  (inner scale)
ALT  = 180° − 0° = 180°
Zero angle

How to Use a Protractor — Online Angle Measurement Practice

A protractor is an instrument used to measure and lay out angles in engineering drawing, sheet metal work, carpentry, and general fabrication. This free online simulator measures angles from 0° to 180° using an interactive rotating arm with a 1° least count.

How to Read a Protractor — Step by Step

Step 1: Place the centre point of the protractor at the vertex of the angle. Step 2: Align the baseline (0° line) with one arm of the angle. Step 3: Read the scale where the second arm crosses the protractor. Check whether you need the inner or outer scale — the simulator shows both.

Inner Scale vs Outer Scale

A semicircular protractor has two scales reading in opposite directions. The inner scale reads left-to-right (0°–180°); the outer scale reads right-to-left (180°–0°). Always confirm which scale aligns with your baseline before reading the measurement.

Angle Classification

This simulator classifies each reading: Acute (0°–90°), Right angle (90°), Obtuse (90°–180°), and Straight angle (180°) — reinforcing angle classification alongside measurement practice.

Who Uses This Simulator?

Ideal for technical drawing students, sheet metal apprentices, carpentry trainees, and students in engineering diploma or TVET programmes who need to demonstrate accurate angle measurement in practical assessments.