Question

find the radius of a circle whose circumference is equal to the sum​

Answer 1

Step-by-step explanation:

Solution: Let the radius of a circle be r. ∴ Circumference of a circle = 2πr Let the radii of two circles are r and r whose values are 15 cm and 18 cm respectively. i.e. r1 = 15 cm and r2 = 18 cm Now, by given condition, Circumference of circle = Circumference of first circle + Circumference of second circle ⇒ 2πr = 2πr1 + 2πr2 ⇒ r = r1 + r2 ⇒ r = 15 + 18 ∴ r = 33 cm Hence, required radius of a circle is 33 cm.Read more on Sarthaks.com - https://www.sarthaks.com/124007/find-the-radius-circle-whose-circumference-equal-the-sum-the-circumference-circles-radii

Answer 2

Answer:

Step-by-step explanation:

we know that

the circumference of circle = 2πr

where r is the radius

now.

the circumference of circle of radius 15 cm = 2π×15= 30π cm

&

the circumference of circle of radius 18cm = 2π×18 = 36π

According to question

the circumference of circle whose radius is r = 30π+36π = 66π

=> 2πr =66π

=> r = 33 answer