Question

the slant height and radius of a cone are 45 cm and 27cm. Find its height.​

Answer 1

Answer:

l=√h2+(r1−r2)2 . So, we get slant height l = 49.67 cm.

Step-by-step explanation:

Have a nice day :)

Answer 2

Let 'ℓ' & R be the radii of the bottom and top circular ends of a frustum of a cone, respectively and 'h' be height of cone.
Volume of the frustum of the cone =
3
1
​
×
7
22
​
×45(28
2
+7
2
+28×7)cm
3

=
7
22
​
×15(784+49+196)cm
3

=
7
22
​
×15×1029cm
3
=22×15×147cm
3

=330×147cm
3

Now, l=
h
2
+(R−r
2
)
​
=
(45)
2
+(28−7)
2

​
=
2025+441
​
=
2466
​

=
2466
​
=49.65cm
curved surface area of the frustum of the cone
=π(R+r)ℓ=[
7
22
​
∗(28+7)∗49.65]cm
2

=[22×5×49.65]cm
2

5461.5cm
2

total surface area of frustum of the cone
π(R+r)ℓ+πR
2
+πr
2

=[5461.5+
7
22
​
×(28)
2
+
7
22
​
×(7)
2
]cm
2

=[5261.5+
7
22
​
×(28)
2
+(7)
2
]cm
2

=[5461.5+22×1+9]cm
2

=8079.5cm
2