Work out similar triangles instantly with clear inputs, formula shown and shareable results.
Similar triangles have equal angles and proportional sides. One pair of corresponding sides fixes the scale factor k; every other length multiplies by k, areas by k² and volumes by k³.
Scale factor
k = side₂ ÷ side₁, area ratio = k², volume ratio = k³
Any of AA (two equal angles), SSS (all three side ratios equal) or SAS (two side ratios equal with the included angles equal) is sufficient.
Area depends on two length dimensions, so each of them is multiplied by k, giving k × k.