| True area | On the old Mercator map | Distortion vs truth |
|---|
| Vietnam | 328,959 km² | 358,565 km² | 1.1× |
| Greenland | 2,154,754 km² | 25,447,645 km² | 11.8× |
| Africa | 30,370,000 km² | — | 1× |
Old maps drew Vietnam at about 358,565 km² km². The truth is 328,959 km² km² — a difference of 9%% that school atlases carried for centuries.