It is known that the base radius of the cone is 2 cm and the generatrix length is 12 cm. If the side of the cone is expanded, the central angle of the sector can be calculated

It is known that the base radius of the cone is 2 cm and the generatrix length is 12 cm. If the side of the cone is expanded, the central angle of the sector can be calculated

The center angle is 60 degrees
First, find the circumference of the cone bottom: C = 2 π r = 2 * π * 2 = 4 π,
The circumference of the bottom surface of the cone is the same as the arc length of the fan-shaped part expanded on the side. The calculation method of the arc length is 2 π R * (center angle / 360) = 4 π, where R is 12 cm, that is, the generatrix length of the cone. The center angle is 60 degrees

The arc length of a conical sector is ()

The arc length of a conical sector is that of a bottom circle

If the side view of a cone is a sector with an arc length of 6 π and a center angle of 90 °, the radius of the bottom circle, the height of the cone and the side area of the cone are calculated

If the side expanded view is a sector with arc length of 6 π and center angle of 90 °, then 1 / 4 * π * 2R = 6 π, sector radius r = 12, and side area of cone = 1 / 4 * π * r * r = 36 π
The arc length 6 π is the circumference of the base circle, 2 π r = 6 π, and the base circle radius r = 3
The height of cone needs Pythagorean theorem. I don't know if you learn it. 3 ^ + H ^ = 12 ^, H = √ 135

The side view of a cone with height of 16cm and bottom radius of 10cm is a sector. What is the arc length of the sector?

The arc length of the sector is the circumference of the ground, 2 * pi * r = 20pi

If the side expansion of a cone is a sector with an arc length of 16 π, then the bottom radius of the cone is______ ．

The solution of 16 π = 2 π R is r = 8

The generatrix of the cone is 5cm in length and 4cm in height. In its side view, the central angle of the sector is______ ．

The radius of the bottom of the cone is 52-42 = 3, the circumference of the bottom of the cone is 2 × π· 3 = 6 π, ∵ L = n ∵ π· R180, ∵ n = 216 degree

If the generatrix length of a cone is 5cm and the radius of its bottom is 3cm, the area of its side expanded view is______ Cm2 (result retention π)

The area of the expanded side view of the cone is 12 × 2 π × 3 × 5 = 15 π (cm2), so the answer is 15 π

If the radius of the cone bottom is 5cm and the side area is 65, the cosine of the angle between the generatrix of the cone and the height is

s=1/2*2π*5*L =65π
L=13
sinX=r/L=5/13
So the square of cosx = 1-5 / 13 = 12 / 13
Your praise is my motivation
I drink Coca Cola in the desert, sing karaoke, ride a lion, drive ants, and answer questions for you with a keyboard in my hand!

(Sanming, 2008) given that the generatrix length of a cone is 5cm and the side area is 15 π cm2, the radius of the bottom circle of the cone is ()
A. 1.5cmB. 3cmC. 4cmD. 6cm

If the radius of the bottom surface is r, then the perimeter of the bottom surface is 2 π R, the side area is 12 × 2 π R × 5 = 5 π r = 15 π, and ψ r = 3cm

Given that the bottom radius of the cone is 5cm and the side area is 65 π cm2, let the angle between the generatrix and the height of the cone be θ, as shown in the figure, then the value of sin θ is ()
A. 512B. 513C. 1013D. 1213

According to the radius of the bottom of the cone is 5cm, the perimeter of the bottom is 10 π. According to the area formula of the sector s = 12L · R, then 65 π = 12.10 π· R, ∧ r = 13, so sin θ = 513. So B