Stand straight up with your back against a wall. Take a book and tuck it between your legs. Pull up the book, simulating the pressure of sitting on a bike saddle. Make a mark on the wall with tape and measure the distance between the top of the book and the ground.
Stand straight with your back against a wall and place a book on your head. Make sure the book is parallel with the floor and at right angles to the wall, touching the wall. Make a mark on the wall with tape and measure the distance between the bottom of the book and the floor.
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