The length of the hypotenuse of a right triangle, which other two sides are 3 cm length and 4 cm, is (a) 10 cm (b) 5 cm (c) 4 cm (d) 3 cm
Answers
Answered by
2
Step-by-step explanation:
The double cone so formed by revolving this right-angled triangle ABC about its hypotenuse is shown in the figure.
Hypotenuse, AC = 32+42
=9+16=25=5 cm
Area of ΔABC=21×AB×AC
⇒21×AC×DB=21×4×3
⇒21×5×DB=6
So, DB = 512=2.4 cm
The volume of double cone = Volume of cone 1 + Volume of cone 2
=31πr2h1+31πr2h2
=31πr2[h1+h2]=31πr2[DA+DC]
=3
Answered by
1
Step-by-step explanation:
3²+4²=root of 9+16
3²+4²=root of 9+16 =√25 = 5
so option b is correct
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