How are u supposed to find the area only with the circumference?

Mathematics

2 answers:

seraphim [82]3 years ago

6 0

Answer:

We can find the radius from circumference and then area

Circumference(C) = 2πr

r = C/2π

r = 20/2π

r = 10/π

Area = πr²

Area = π × 10/π × 10/π

Area = 100/π

Area = 100/3.14

Area = 10000/314 = 31.84 cm² (approx)

Area = 32 cm² (Rounding to nearest whole number)

Dima020 [189]3 years ago

4 0

Answer:

32 m²

Step-by-step explanation:

We need to work out the area of the flower garden when we are given the circumference. First we need to know the formula's for area of circle and circumference of circle which are

→ Area of a circle = π × r² where 'r' is the radius

→ Circumference of a circle = 2 × π × r where 'r' is the radius

So we need to form an equation with the circumference of a circle formula and work out the radius in order to find the area so,

In an equation our aim is to find the value of what we are looking for as well as keeping the equation balanced. For example if we divided by 2 only from one side then the equation would change so it's an important rule to keep in mind when solving equations, that you need to keep both sides of the equation the same.

2 × π × r = 20

→ Substitute 3.14 for π

2 × 3.14 × r = 20

→ Simplify

6.28 × r = 20

→ Divide both sides by 6.28 to isolate 'r'

r = 3.18471338

So now we now the radius of the circle we can substitute the radius into the area of circle formula

Area = π × r²

→ Substitute 3.14 for π and r for 3.18471338

Area = 3.14 × 3.18471338²

Area = 31.847133842