The area of two similar triangles $A B C$ and $P Q R$ are in the ratio $9 : 16$ . If $B C = 4.5 c m$ , find the length of $Q R$ .

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Solution

Given $△ A B C \sim △ P Q R$

$∴ \frac{a r e a (△ A B C)}{a r e a (△ P Q R)} = \frac{B C^{2}}{Q R^{2}}$

$⟹ \frac{9}{16} = \frac{{4.5}^{2}}{Q R^{2}}$

$Q R = \frac{4 \times 4.5}{3}$

$∴ Q R = 6$ cm

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The area of two similar triangles ABC and PQR are in the ratio 9:16. If BC=4.5cm, find the length of QR.

Given △ABC∼△PQR ∴area(△ABC)area(△PQR)=BC2QR2⟹916=4.52QR2QR=4×4.53∴QR=6cm

The area of two similar triangles $A B C$ and $P Q R$ are in the ratio $9 : 16$ . If $B C = 4.5 c m$ , find the length of $Q R$ .

Given $△ A B C \sim △ P Q R$

$∴ \frac{a r e a (△ A B C)}{a r e a (△ P Q R)} = \frac{B C^{2}}{Q R^{2}}$

$⟹ \frac{9}{16} = \frac{{4.5}^{2}}{Q R^{2}}$

$Q R = \frac{4 \times 4.5}{3}$

$∴ Q R = 6$ cm