Linear scale factorSimilar shapes

Similar figures are identical in shape, but generally not in size. A missing length on a reduction/enlargement figure can be calculated by finding its linear scale factor.

Part of MathsAngle, symmetry and transformation

Similar shapes

Similar figures are identical in shape, but generally not in size.

For example, two circles are always similar:

Two circle shapes of equal proportions, one smaller than the other

Two squares are always similar:

Two square shapes, one smaller than the other

And two rectangles could be similar:

Two rectangle shapes of equal proportions, one smaller than the other

But often will not be:

Two rectangle shapes of unequal proportions