Question

A ladder 10 m long reaches a window above the ground. The distance of the foot of the ladder from the base of the wall is 6 m. Then the height of the ladder from the ground is

• A. $8m$
• B. $6.5m$
• C. $7m$
• D. $6m$

Answer 1

The correct option is A

$8m$

Let BA be the wall and AC be the ladder.
Therefore, by Pythagoras theorem, we have,
$A{C}^2=A{B}^2+B{C}^2$
${10}^2=A{B}^2+6^2$
$A{B}^2=100-36$
$A{B}^2=64$
$AB=8$ m
Therefore, the height of the ladder from the ground is $8$ m.