
Length of the book (hypotenuse) = 13 inches
Distance of the book from the foot of the wall (base) = 5 inches

Length of the book on the wall (perpendicular ''
").


By Pythagoras theorem, we have
(Perpendicular)² + (Base)² = (Hypotenuse)²
+ (5 in) ² = (13 in)²
+ 25 in² = 169 in²
= 169 in² - 25 in²
= 144 in²
=

=

=

= 12 in
Therefore, the height of the book on the wall
is 12 inches.
