Maths · KS3 Y9 · Geometry & Measures

Similar shapes

Similar shapesFree2:06Heddy Score 3 of 7, below the standard

What you need to know

  • A scale factor is the number you multiply by to get from one shape to the similar one.
  • Find it by dividing a new length by the matching old length.
  • A scale factor greater than 1 is an enlargement and less than 1 makes the shape smaller.
  • Reversing the direction gives the reciprocal scale factor, for example 5/2 and 2/5.

In this clip

0:00–1:58Scale factors as multipliers
Also coversSimilar shapes
Heddy Score3/7, Below the standard
See the seven stars
  • Trusted source · passed. The creator's own upload, live and playable here.
  • On the map · not judged yet. A teacher watched it: it mainly teaches this map topic.
  • Spec-true · not judged yet. Accurate, and right for the current UK specification.
  • Focused · passed. One idea, short enough to watch in one go.
  • Accessible · passed. Good captions, clear sound and pictures.
  • Safe for children · not judged yet. Right for 11 to 16 year olds, with no sales pitch.
  • Proven · not judged yet. Earned from our students: they learn from it, find it helpful and watch it to the end.
★ passed · ☆ pending · ✕ failed
Our students

Not enough students yet

Our own students' answers. These are what move ★7 Proven.
On YouTube

632K views · 5.66K likes · Mario's Math Tutoring 533K subscribers

As reported by YouTube on 2026-11-03. Not part of the Heddy Score.
How the Heddy Score works

Why we picked it

A quick, focused explanation of scale factor as new ÷ old, including factors below 1.

Mario's Math Tutoring on YouTubechecked 2026-10-22

Plays from youtube-nocookie.com. No YouTube cookies until you press play.