Sheet #22

1. 01

   ReferenceAdult hand18.9 cm

   To size upA4 sheet29.7 cm

   Measured Height of an A4 sheet (ISO 216)

   Fold an A4 in half and you get A5: the side ratio stays √2.

2. 02

   ReferenceLight bulb11 cm

   To size upCity bike1.75 m

   Measured Length of an adult city bike

   A 28-inch wheel is about 70 cm across, tyre included.

3. 03

   ReferenceStarship121 m

   To size upEmpire State Building381 m

   Measured Roof height of the Empire State Building

   It was built in one year and 45 days, in 1930–1931.

4. 04

   ReferenceServer rack1.87 m

   To size upOak tree25 m

   Measured Height of a mature English oak

   An oak can live for several centuries.

5. 05

   ReferenceDiplodocus25 m

   To size upInternational Space Station109 m

   Measured Span of the International Space Station, solar arrays included

   It circles the Earth in about 90 minutes.

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