The area of a circle is 81pi in. squared. What is the circumference, in inches? Express your answer in terms of pi

18π

Step-by-step explanation:

the area of a circle is :

A= r²*π     where r is the radius

here r²  =81⇒ r= 9

the circumference of a circle is :

P= 2*r*π

P= 18π

18 pi inches

Step-by-step explanation:

The area of a circle is given by

A = pi r^2

81 pi = pi r^2

Divide by pi

81 = r^2

Take the square root of each side

sqrt(81) = sqrt (r^2)

9 = r

We want the circumference

C = 2 * pi * r

C = 2 * pi * 9

C = 18 pi

option a, c,d are correct.

step-by-step explanation:

from the given figure, it is given that z is equidistant from the sides of the triangle rst, then from triangle tzb and triangle szb, we have

tz=sz(given)

bz=zb(common)

therefore, by rhs rule,δtzb ≅δszb

by cpctc, sz≅tz

also, from δctz and δasz,

tz=sz(given)

∠tcz=∠saz(90°)

by rhs rule, δctz ≅ δasz, therefore by cpctc, ∠ctz≅∠asz

also,from δasz and δzsb,

zs=sz(common)

∠zbs=∠saz=90°

by rhs rule, δasz ≅δzsb, therefore, by cpctc, ∠asz≅∠zsb

hence, option a, c,d are correct.

7! = 7×6×5×4×3×2

3! = 3× 2

as 7! is multiple of 3! because 7! contains 3! that is 3× 2 as factor

so 7! /(3! ) = 7× 6× 5× 4

= 42 × 20

= 840

its b) 840✌✌✌

dhruv⭐