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3 years ago

Calculate the area of a circle with a radius of 2 cm and a circle with a radius of 4 cm. Leave your answers in terms of pi.

Mathematics

1 answer:

galina1969 [7]3 years ago

6 0

S = πr^2
so area of circle where r is 2cm;π=3,14 will be
S = π*(2^2)
S=π*4
S=4π cm2

S = πr^2
so circle where r is 4cm;π=3,14 will be
S = π*(4^2)
S=π*16
S=16π cm2

the answer for second question is thet the area gets bigger 4 times if we double radius)so "yes"

ANSWER IS
C) 4π cm2; 16π cm2; YES

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777dan777 [17]

Answer:

x = 65

Step-by-step explanation:

The angle labeled with the expression " ( 2x + 15 ) " and the angle with the measure of 145° are vertical angles

Vertical angles are congruent (In other words, they are equal to each other)

Hence, 2x + 15 = 145

^ ( Note that we just created an equation that we can use

to solve for x )

Using that same equation we then solve for x

2x + 15 = 145

step 1 subtract 15 from each side

15 - 15 cancels out

145 - 15 = 130

we now have 130 = 2x

step 2 divide each side by 2

130 / 2 = 65

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we're left with x = 65

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3 years ago

A cone and a sphere both have a radius of 1. If you fill the cone with liquid, and pour it into the sphere, it fits exactly. Wha

PtichkaEL [24]

Answer and Step-by-step explanation:

First, solve for the volume of the sphere, then solve for the height of the cone using the volume of the sphere (which is said to be equal to the volume of the cone) and the radius given.

Volume formula of Sphere

V = $\frac{4}{3} \pi r^2$

Substitute 1 in for r

$\frac{4}{3} \pi (1)^2 = \frac{4}{3} \pi = 4.189$ = Volume

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Volume formula for Cone: $V = \pi r^2\frac{h}{3}$

Solve for h

Multiply both sides by 3, then divide by pi and r^2.

$h = \frac{3V}{\pi r^2}$

Plug in the volume and the radius.

$h = \frac{3(4.189)}{\pi (1)^2}$

Simplify

$h = \frac{12.567}{\pi }$

h ≈ 4

4 is approximately the height.

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3 years ago

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Yanka [14]

Step-by-step explanation:

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