FREE DOWNLOAD
Help your students prepare for their Maths GCSE with this free arcs and sectors worksheet of 40 questions and answers
You can unsubscribe at any time (each email we send will contain an easy way to unsubscribe). To find out more about how we use your data, see our privacy policy.
An arc of a circle is a portion of the circumference of a circle. To find the length of an arc, we adapt the formula for the circumference of a circle ΟD, where D is the diameter of the circle. We need to divide the angle of the sector by 360, and multiply this by ΟD to find the length of the arc. Essentially we are finding the required proportion of the circumference of the circle.
A sector of a circle is a portion of a circle enclosed by two radii and an arc. To find the area of a sector we need to adapt the formula for the area of a circle rΒ², where r is the radius of the circle. A simple example is calculating the area of a semicircle. Here we need to find the area of the whole circle and then divide by 2; this is because a semicircle is half of a circle. For other sectors, we need to divide the angle of the sector by 360 and then multiply this by ΟrΒ² to find the area of the sector.
The algebraic formula for arc length and area of a sector frequently use Ξ for the angle at the centre of the circle so it is important that students recognise this notation.
The perimeter of the sector can be found by summing the arc length and two lots of the length of the radius. As problems involving arcs and sectors use Ο, answers will often require rounding to a given number of decimal places or significant figures. This topic can be extended further to involve finding the area of a segment which often also requires applications of trigonometry.
Looking forward, students can then progress to additional circles, sectors and arcs worksheets and otherΒ geometry worksheets, for example anΒ angles in polygons worksheetΒ orΒ area andΒ circumference of a circle worksheet.
For more teaching and learning support on Geometry our GCSE maths lessons provide step by step support for all GCSE maths concepts.Β
With Third Space Learning's secondary maths tutoring programmes, students in Year 7-11 receive regular one to one maths tutoring to address gaps, build confidence and boost progress.
"My confidence in the tutoring is high. We've had some phenomenal results. I even had one girl get a Grade 8 this year; she came to every tutoring session."
Stacey Atkins, Maths Director, Outwood Grange Academies Trust