The formula for finding the area of ​​a cone blanket and examples of the problem

Cone Blanket Area FormulaOf course you often see or encounter objects that are shaped like cones. Farmers hats, rice cones, or birthday hats are examples of conical objects. Because it has been discussed before The formula for finding the volume of a cone with examples of the problem then this time the material that will be given by basic math formula is about how to calculate and find the area of ​​the blanket from the shape of a conic space. If you notice, a cone has a wedge (bottom) side that is circular. While the part that forms an acute angle is a curved area known as a conical blanket. So, a cone has two sides, the first side is the wedge side while the second side is the blanket side. See the following image:

Of course you often see or come across objects Formulas for Finding the Area of ​​a Cone Blanket and Examples of Problems

In the cone image above the height of the cone is denoted by the letter t, characters r is the radius of the cone, while the character s is a painter’s line.

Formulas for Calculating the Area of ​​a Cone Blanket Example Problems and Discussion

If a cone is cut by following the painter’s line, it will form a net of cones like this:

Of course you often see or come across objects Formulas for Finding the Area of ​​a Cone Blanket and Examples of Problems

Also read: How to calculate the formula for the volume of a cylinder (cylinder)

Take a look at the picture above. The area of ​​the cone is the result of the sum of the area of ​​A and the area of ​​CBB. Well, to find out the surface area of ​​a cone, you must first find out the area of ​​the blanket. The area of ​​a conical blanket can be found using the following formula:

Area of ​​blanket of cone = sr

= 22/7 = 3.14
s = length of the painter’s line
r = radius

Let’s look at the reference to the use of this formula in answering the following questions:

Example question 1

It is known that a cone has a radius of 3 cm and the length of the painter’s line is 5 cm. Then determine:

A. the height of the cone
B. volume of cone
C. the area of ​​the cone blanket
D) the surface area of ​​the cone

How to answer:

A. Height of cone

To find the height of the cone, we can use the Pythagorean formula like this:

t2 = s2 – r2
t2 = 52 – 32
t2 = 25 – 9
t2 = 16
t = 16 = 4cm

B. Volume of cone
V = 1/3 r2 t
V = 1/3 x 3.14 x 3 x 3 x 4
V = 3.768 cm3

c. Cone blanket area
L = rs
L = 3.14 x 3 x 5
L = 471 cm2

D. Surface area of ​​the cone
L = r(s + r)
L = 3.14 x 3 (5+3)
L = 3.14 x 3 x 8 = 75.36 cm2

Well, that’s roughly the formula and method that you can use to find the area of ​​a conical blanket. Study the reference questions given carefully and slowly. Hopefully it can make it easier for you to be able to understand math lesson material about The formula for finding the area of ​​a cone blanket what your teacher taught you at school.