Junior Cycle · Geometry
⏱ Tested in 3 exam questions since 2023
Lesson 6 of 12
JCHL Geometry 6: Similar Triangles
This tutorial is for members
Read the lesson notes free below — subscribe to watch the full worked video and download the PDF.
Subscribe for full access · €199/yrLearning work
- Similar = same angles, so the sides are in PROPORTION (one triangle is a scaled copy of the other)
- To prove similar: show TWO pairs of equal angles (the third pair is then automatic), justifying each
- Then write the fractions of corresponding sides and sub in to find the unknown
- Sides correspond when they are OPPOSITE equal angles. Redraw overlapping triangles separately
Most recent exam questions
- 2025 Q6(b)(ii)
- 2025 Q6(c)
- 2024 Q13(c)(i)
- 2023 Q14(b)
💬 Stuck on something in this lesson?
Send your question with this lesson’s name attached — you’ll get a reply by email.