Question

The area of two similar triangles ABC and PQR are 25 $c{m}^2$ and $49c{m}^2$ If QR=9.8 cm then BC is

• A. 9.0 cm
• B. 7 cm
• C. 49 cm
• D. 41 cm

Answer 1

The correct option is B 7 cm

If two triangles are equals than the ratio of their square is equal to the ratio of their corresponding sides.

$\therefore \frac{arc\left(△ABC\right)}{arc\left(△PQR\right)}=\frac{B{C}^2}{Q{R}^2}$

$\Rightarrow \frac{25}{49}=\frac{B{C}^2}{(9.8{)}^2}$

$\Rightarrow \frac{5}{7}=\frac{BC}{9.8}$

$\Rightarrow BC=\frac{9.8\times 5}{7}=7.0c{m}^2$