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प्रश्न
In a right-angled triangle ABC, if angle B = 90°, BC = 3 cm and AC = 5 cm, then the length of side AB is ______.
विकल्प
3 cm
4 cm
5 cm
6 cm
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उत्तर
In a right-angled triangle ABC, if angle B = 90°, BC = 3 cm and AC = 5 cm, then the length of side AB is 4 cm.
Explanation:
In right angled ΔABC,
AC2 = AB2 + BC2 ...[By Pythagoras theorem]
⇒ 52 = AB2 + 32 ...[∵ AC = 5 cm and BC = 3 cm, given]
⇒ AB2 = 25 – 9
⇒ AB2 = 16
⇒ AB = `sqrt(16)`
⇒ AB = 4 cm
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