$ABC$ is a triangle, right-angled at $C$. If $AB=25\ cm$ and $AC=7\ cm$, find $BC$.

AcademicMathematicsNCERTClass 7

Given :

$ABC$ is a right-angled triangle at $C$.

$AB= 25$ cm and $AC = 7$ cm.

To do :

We have to find the value of BC.

Solution :

Angle C is the right angle, this implies, that AB is the hypotenuse.

Therefore,

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

$\Rightarrow (25)^2=(7)^2+BC^2$

$\Rightarrow BC^2 = 625 - 49$

$\Rightarrow BC^2 = 576$

$\Rightarrow BC^2 = 24 \times 24$

$\Rightarrow BC = 24$ cm

The length of BC is 24 cm.

raja
Updated on 10-Oct-2022 13:34:29

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