Given:
radius of cone = r
height of cone = h
radius of cylinder = r
height of cylinder = h
slant height of cone = l
Solution
The lateral area (A) of a cone can be found using the formula:

where r is the radius and l is the slant height
The lateral area (A) of a cylinder can be found using the formula:

The ratio of the lateral area of the cone to the lateral area of the cylinder is:

Canceling out, we have:

Hence the Answer is option B
Area = π x r^2
Area = π x 12^2
Area = 144π or 452.16 square units. ( using 3.14 for PI)
Circumference = 2*PI *radius
Circumference = 12π or 37.68 units ( using 3.14 for PI)
Answer:

Step-by-step explanation:

Answer:
The value of a which equation have 2 , -
Step-by-step explanation:
Given expression as :
2 a - 4 x = 4 - a² × x
The equation lies in the interval ( - 8 , - 2 )
∵ equation lies in the interval , so it must satisfy the equation
So , 2 a - 4 × ( - 8 ) = 4 - a² × ( - 8 )
Or, 2 a + 32 = 4 + 8 a²
Or, a + 16 = 2 + 4 a²
So, equation can be written as :
4 a² - a - 14 = 0
Or, 4 a² - 8 a + 7 a - 14 = 0
Or, 4 a ( a - 2 ) + 7 ( a - 2 ) = 0
Or, ( a - 2 ) ( 4 a + 7 ) = 0
∴ a = 2 And -
Hence The value of a which equation have 2 , -
Answer