Given
Area of the regular pentagon is 6.9 cm².
Find out the perimeter of a regular pentagon
To proof
Formula
Area of regular pentagon is

As given in the question
area of regular pentagon = 6.9 cm²
now equating the area value with the area formula.

Now put
√5 = 2.24 ( approx)
put in the above equation

thus
a² = 4.01
a = √ 4.01
a = 2.0 cm ( approx)
As perimeter represented the sum of all sides.
i.e regular pentagon have five sides of equal length.
Thus
perimeter of the regular pentagon = 5 × side length
= 5 ×2.00
therefore the perimeter of the regular pentagon = 10cm
option c is correct
Hence proved
Answer:
24
Step-by-step explanation:
let 'x' = number
x/2 - 2 = 10
add 2 to each side to get:
x/2 = 12
cross-multiply to get:
x = 24
Answer:
-6
Step-by-step explanation:
Substitutet -7 for y in -3(9+y): -3(9 - 7) = -3(2) = -6
Take the common denominator and divide by 3