Ask question

Ask question

All categories

3 years ago

13

What is the area and the circumference of a circle with a diameter of 8 m.

1 answer:

Elenna [48]3 years ago

8 0

Answer:

50.27m

2 π r

Step-by-step explanation:

You might be interested in

A lampshade has a height of 12cm and upper and lower diameters of 10cm and 20cm A)what area of material is required to cover tha

netineya [11]

Answer:

$(a)\ Area = 195\pi$

$(b)\ Volume = 700\pi$

Step-by-step explanation:

Given

$h = 12$

$d_1 = 10$ --- lower diameter

$d_2 = 20$ --- upper diameter

Solving (a): The curved surface area

This is calculated as:

$Area = \pi l(r_1 + r_2)$

Where

$r_1 = 0.5 * d_1 = 0.5 * 10 = 5$ --- lower radius

$r_2 = 0.5 * d_2 = 0.5 * 20 = 10$ --- upper radius

And

$l = \sqrt{h^2 + (r_1 - r_2)^2$ ---- l represents the slant height of the frustrum

$l = \sqrt{12^2 + (5 - 10)^2$

$l = \sqrt{12^2 + (-5)^2$

$l = \sqrt{144 + 25$

$l = \sqrt{169$

$l = 13$

So, we have:

$Area = \pi l(r_1 + r_2)$

$Area = \pi * 13(5 + 10)$

$Area = \pi * 13(15)$

$Area = 195\pi$

Solving (b): The volume

This is calculated as:

$Volume = \frac{1}{3}\pi * h * (r_1^2 + r_2^2 + (r_1 * r_2))$

This gives:

$Volume = \frac{1}{3}\pi * 12 * (5^2 + 10^2 + (5 * 10))$

$Volume = \frac{1}{3}\pi * 12 * (25 + 100 + (50))$

$Volume = \frac{1}{3}\pi * 12 * (175)$

$Volume = \pi *4 * 175$

$Volume = 700\pi$

6 0

3 years ago

What is the equation of the line that contains the point 46x30 and has a slope of -3?

BARSIC [14]

Answer:

$y=-3x+30$

Step-by-step explanation:

Written in: y=mx+b

6 0

3 years ago

What is the answer of 81g^2 - 36f^2 ?????

sveticcg [70]

Answer:

(9g - 6f)(9g + 6f)

Step-by-step explanation:

81g^2 - 36f^2 =

(9g)² - (6f)² =

(9g - 6f)(9g + 6f)

3 0

2 years ago

The ratio of peter's height to albertina's height is 147cm what is peter's height

stellarik [79]

Answer:

4'9.87

Step-by-step explanation:

8 0

2 years ago

If an item that originally cost $13 is increased to $19, what is the percentage of increase in the item?

Evgesh-ka [11]

Original cost (OC) = $13

New cost (NC) = $19

Percentage increase = $\frac{NC - OC}{OC} *100 = \frac{19 - 13}{13} * 100 = \frac{6}{13} * 100$

= 46.15 %

4 0

3 years ago