All categories

3 years ago

What is the surface area of the cone? (Use 3.14 for π.)

Mathematics

2 answers:

aev [14]3 years ago

4 0

Answer: 117.226666667 cm^3

Step-by-step explanation:

So, we all know the formula for working out the volume of a cone is

V= 1/3πr^2h

V = 1÷3 x 3.14 × r^2 x h

The radius is half the diameter. Your diameter is 8 so the radius would be 4. And 7 is your height by the way.

So let's plot it all in!

V= 1÷3 x 3.14 × 4^2 x 7

V = 117.226666667cm^3

Round to the nearest 10 = 117.2cm^3

To the nearest 100 = 117.23cm^3

To the nearest whole number = 117cm^3

frozen [14]3 years ago

3 0

Answer:

Surface area = 87.92 Sq Inch and Total surface area =138.16 Sq Inches

Step-by-step explanation:

Here we are required to find the surface area of a cone, The formula of surface area of a cone is given as under

r=4

l = 7

$S_{s}=\pi*r*l$

$S_{s}=3.14*4*7$

$S_{s}=87.92$

Also the total surface area is given as

$T_{s}=\pi*r^{2} + \pi*r*l$

We are given

Now we put the values of r and l in main formula

$s=\pi*4^{2} + \pi*4*7\\s=3.14*16+3.14*28\\s=50.24+87.95\\s=138.16$

Hence the Surface area is 87.92 sq inches and Total surface area of the cone is 138.16

You might be interested in

Find the slope of the line through each pair of points.

Lady bird [3.3K]

You can use this formula: (y1 - y2) / (x1-x2)

For example, using question 5,

(-11-16)/ [-6-(-20)]
= -17/14

Given that it is a negative number, it would mean that the line is downward-sloping.

All the best!

8 0

3 years ago

Please help me asap with my grade 11 trigonometry math! I'll give brainliest, please help, thank you. *URGENT*

tia_tia [17]

Answer:

37.8579

This value is approximate and rounded to four decimal places

===============================================

Explanation:

The tangent function is being applied to some unknown angle x. To isolate x, we undo whatever tangent is doing. So we apply the inverse function. Specifically the inverse tangent function. This is also known as "arctangent" and your calculator most likely shows it as a button with a "-1" exponent above the "tan"

So apply the arctangent to both sides to get

tan(x) = 0.7773

arctan(tan(x)) = arctan(0.7773)

x = 37.8579

6 0

2 years ago

Read 2 more answers

A submarine is 600 feet below sea level. It is rising to the surface at a rate of 15 feet per hour. Which expression represents

matrenka [14]

15 × h
h= per hour

and to solve how many hours it would take:

600= 15 × h

600÷ 15 = 40

so it would take 40 hours to rise to the surface

7 0

3 years ago

Please help with geometry

Alexandra [31]

The way to do this is to set up a 30 degree angle in a coordinate plane in the first quadrant. I say the first quadrant since the first quadrant goes from 0 to 90 degrees and 30 falls right in that interval. Using the positive x-axis as the initial ray of the 30 degree angle and the terminal ray of the angle as the hypotenuse of a right triangle, if we drop a height from the end of the terminal ray to the x-axis we have formed said right triangle. The angle at the origin is the 30 degree angle. According to the Pythagorean triple for a 30-60-90 triangle, the side across from the 30 degree angle measures 1, which is the height of our triangle. The side across from the 60 degree angle is square root of 3, which is the base of our triangle, and the hypotenuse is 2. The cos identity is the ratio that utilizes the side adjacent to the reference angle over the hypotenuse, which for us is $\frac{ \sqrt{3} }{2}$ . That's the third choice down. Finding an "exact" value means that they want you to NOT express your answer in decimal form.

4 0

3 years ago

Wayne is solving a system of linear equations.

Ulleksa [173]

Answer:

(-2, 6.5)

Step-by-step explanation:

Wayne can follow the line from (-2, 0) up to where it crosses the graphed line. The crossing point is approximately halfway between 6 and 7 on the graph, so can be considered to be 6.5.

If we put x=-2 into the equation and evaluate, we get ...

... y = (-3/4)(-2) +5 = 6/4 +5 = (1 1/2) +5 = 6 1/2

Thus the solution is (-2, 6 1/2).

8 0

4 years ago