Question

A ladder of 3.9 m length is laid against a wall. The distance between the foot of the wall and the ladder is 1.5 m. Find the height at which the ladder touches the wall.
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Answer 1

QUESTION :-

A ladder of 3.9 m length is laid against a wall. The distance between the foot of the wall and the ladder is 1.5 m. Find the height at which the ladder touches the wall.

SOLUTION :-

h² = (3.9)² - (1.5)²

= (3.9 + 1.5)(3.9 - 1.5)

= 5.4 × 2.4

= 0.6 × 9 × 0.6 × 4

= (0.6)² × 6²

.°. h = 6 × 0.6 = 3.6 m

Answer 2

Given,

${h}^{2} = {3.9}^{2} - {1.5}^{2}$

$= (3.9 + 1.5)(3.9 - 1.5)$

$= 5.4 \times 2.4$

$= 0.6 \times 9 \times 0.6 \times 4$

$= {0.6}^{2}$

$= {6}^{2}$

$h = 6 \times 0.6$

$= 3.6m$