Конус втягивается в пирамиду, основание которой представляет собой правильный треугольник со стороной 2 см. Боковая грань пирамиды образует с плоскостью основания угол 45°. Вычислите объем конуса.
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Answer:
Решение
проверено
Проверено Топпр
Двойной конус, образованный вращением прямоугольного треугольника ABC вокруг его гипотенузы, показан на рисунке.
Гипотенуза, АС =
3
2
+4
2
знак равно
9+16
Solution
verified
Verified by Toppr
The double cone so formed by revolving this right-angled triangle ABC about its hypotenuse is shown in the figure.
Hypotenuse, AC =
3
2
+4
2
=
9+16
=
25
=5 cm
Area of ΔABC=
2
1
×AB×AC
⇒
2
1
×AC×DB=
2
1
×4×3
⇒
2
1
×5×DB=6
So, DB =
5
12
=2.4 cm
The volume of double cone = Volume of cone 1 + Volume of cone 2
= 31 πr
2 h 1+ 31
πr 2h 2
= 31 πr 2 [h 1
+h
2
]=
3
1
πr
2
[DA+DC]
= 31
×3.14×2.4
2
×5
=30.14 cm
3
The surface area of double cone = Surface area of cone 1 + Surface area of cone 2
=πrl
1+πrl
2
=πr[4+3]=3.14×2.4×7
=52.75 cm
2
Answer:
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Explanation:
Do you have a garden? Do you know the names of all the flowers that bloom in your garden? If not, find them out. Now, knowing the names of flowers, not just the ones you see around you but all around