A $15\ m$ long ladder reached a window $12\ m$ high from the ground on placing it against a wall at a distance a. Find the distance of the foot of the ladder from the wall.

AcademicMathematicsNCERTClass 7

Given: A $15\ m$ long ladder reached a window $12\ m$ high from the ground by placing it against a wall at a distance $a$.

To do: To find the distance of the foot of the ladder from the wall.

Solution:

Let $AC$ be the ladder, and $A$ be the window

$AC^2=AB^2+BC^2$

$\Rightarrow (15)^2=(a)^2+(12)^2$

$\Rightarrow 225-144=a^2$

$\Rightarrow 81=a^2$

$\Rightarrow \sqrt{81}=a$

$\Rightarrow a=9$
raja
Updated on 10-Oct-2022 13:34:29

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