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प्रश्न
Calculate BC.
उत्तर
In ΔACD, we have
`tan 42^circ = (CD)/(AD)`
`=> 0.9004 = (CD)/20`
CD = 0.9004 × 20 = 18.008 m.
In right ΔABD, we have
`tan 35^circ = (AD)/(BD)`
`=> 0.7002 = 20/(BD)`
`=> BD = 20/0.7002 = 28.56`
∴ BC = BD – CD
= 28.56 – 18.00
= 10.56 m
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