Radius, diameter, and circumference and area of Circles
A circle is a plane round figure in which all points are equidistant from the center.
Radius is a line segment that joins the center of circle to any point on the circumference of circle.
Diameter is a straight line segment passing through the center of circle, the endpoints of which touches the circumference of circle.
Circumference of circle is the distance around the circle.
Circumference of circle = 2π× radius = π× diameter
Area of circle = π× (radius)2
Example:What is the radius of circle with diameter 12 inches?
Radius of circle = = = 6 inches
Example:If the circumference of circle is 88 cm, then what is the radius of circle? (Use π= )
2πr = 88
2 ××r = 88 implies r = 14 cm
- What is the radius of circle with circumference 24π in?
- What is the area of circle with circumference 30.2 yards? Round your answer to the nearest tenth. (Use π = 3.14)
- What is the area of circle with diameter 6 yards? Round your answer to the nearest tenth. (Use π = 3.14)
- What is the diameter of circle with circumference 63 feet? Round your answer to the nearest whole. (Use π = 3.14)
- What is the circumference of circle with area 12.6 in2? Round your answer to the nearest tenth. (Use π = 3.14)
- 12 in.
- 6 yd2
- 3 yd2
- 20 feet
- 6 in
Give Your Child The eTutorWorld Advantage
Research has proven that personal online tutoring not just cements school learning, it helps build student confidence. Come to eTutorWorld for Expert Tutors and best K-12 Online Tutoring Services in the comfort and safety of your home at an affordable cost. Find a tutor online for Grade 3-12 Math, Science and English subjects and AP, SAT, SSAT and SCAT Test Prep help and test practice. Get free printable math and science worksheets in pdf format and SCAT Practice Tests. Sign up for a Free Trial Lesson Today!
© 2018 eTutorWorld - Online Tutoring and Test Prep | All rights reserved