Recent posts View all
Home of real teaching & learning
  • Full support for teachers
  • Focus on critical thinking
  • Engaging classroom activities
  • Integrated student eBook
  • Assessed tasks / qBank
  • Practice exam questions
Find out more Download brochure

The InThinking Guarantee: Our sites are written by expert practitioners and not by AI

See our AI policy

Disclaimer: InThinking subject sites are neither endorsed by nor connected with the International Baccalaureate Organisation.

Don't miss out, find out!
IB Approved Workshops
Physics
IB DP Category 1

Paris, France, 13 - 15 November 2026

Find out more
Physics: A focus on the experimental programme
IB DP Category 3

Paris, France, 19 - 21 February 2027

Find out more
Physics
IB DP Category 2

Berlin, Germany, 26 - 28 February 2027

Find out more
Virtual Think-Ins
Focus On: IB Teaching – A Practical Guide for Teachers new to the IB

20 November 2026

Find out more

Find all InThinking events at
inthinking.net

Measuring angles from photo

Amtul asked how to measure angles on a digital photo of light reflecting off a curved mirror, here's how to do it in GeoGebra.

First I insert the image (a screen shot from Algodoo). Then make it the background (right click object properties). Then I made a circle and adjusted it so that it gave the centre of curvature. A line was placed to act as a normal. The angles can then be measured with angle tool.

Good luck.

Tags: GeoGebra

Help