Question
In the given figure, $\triangle\text{OAB}\sim\triangle\text{OCD}.$ If AB = 8cm, BO = 6.4cm, OC = 3.5cm and CD = 5cm, find.
- OA
- DO
✓
Answer
- Let OA be x cm.
$\therefore\frac{\text{OA}}{\text{OC}}=\frac{\text{AB}}{\text{CD}}$
$\Rightarrow\frac{\text{x}}{\text{3.5}}=\frac{\text{8}}{\text{5}}$ and
$\Rightarrow\text{x}=\frac{8\times3.5}{5}=5.6$
hence, OA = 5.6cm
- Let OD be y cm
$\therefore\frac{\text{AB}}{\text{CD}}=\frac{\text{OB}}{\text{OD}}$
$\Rightarrow\frac{\text{8}}{\text{5}}=\frac{\text{6.4}}{\text{y}}$
$\Rightarrow\text{y}=\frac{6.4\times5}{8}=4$
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