Question

A ladder is placed in such a way that its foot is at a distance of $5$ in from a wall and its tip reaches a window $12m$ above the ground. Determine the length of the ladder.

• A. $13m$
• B. $112m$
• C. $11m$
• D. $15m$

Answer 1

Answer: (A)

$13m$

When a ladder is placed, it will form a right angle triangle $ABC$

$AB$ represents wall and $AC$ represents ladder.

Given : Distance of ladder from wall is $BC=5$ m

Height of window is $AC=12$ m

The wall makes an right angle at window with ladder

In right angle triangle $ABC,$

$(AC{)}^2=(AB{)}^2+(BC{)}^2$

$\Rightarrow (AC{)}^2=(12{)}^2+(5{)}^2=144+25=169$

$\Rightarrow AC=13$ m