Class 7 Maths · Ganita Prakash Part 2 · Chapter 1
Geometric Twins
Congruence — when two figures are exact twins, and how to prove two triangles match without measuring everything.
Video coming soon — meanwhile, watch free classes on our YouTube channel →
Rashmi Ma’am teaches the full chapter free on YouTube — watch first, then practise below.
What your child learns
- Understand congruence as “same shape AND same size” — twins, not lookalikes
- Test congruence by superposition and by matching measurements
- Learn the triangle congruence shortcuts — which three facts are enough
- Write a congruence statement with vertices in the correct order
- Use congruence to explain why constructions and designs work
Parent pointer
The exam skill here is precision: writing △ABC ≅ △PQR with letters in matching order. Marks are lost to sloppy ordering, not wrong understanding. When checking homework, check the letter order — that one habit protects marks into Class 9, where congruence proofs get serious.
Stuck on this chapter? Message us — tell us the exercise number and we’ll point you to the right video.
💬 Ask about this chapterPractise it — the Azone loop
Watch the class
Full chapter above, free. Pause and solve along — that’s the rule.
Quick questions parents ask
Congruent vs similar — what’s the difference?
Congruent = same shape and same size (true twins). Similar = same shape, possibly different size (a photo and its enlargement). Class 7 does congruence; similarity comes in Class 10 and builds directly on this.
Why does my child need to prove it when it’s obviously the same?
“Obvious” fails on tricky figures — and exams exploit that. The shortcuts (like SSS and SAS) teach the deeper idea: a few verified facts can guarantee everything else. That’s the heart of mathematical reasoning.
Want this chapter to actually stick?
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