Siâp a Gofod / Shape and Space

SECTOR CYLCH / SECTOR OF CIRCLE

ARWYNEBEDD SECTOR A HYD ARCAREA OF SECTOR AND ARC LENGTH

Mae modd canfod arwynebedd a hyd arc unrhyw sector o gylchIt’s possible to find the area and arc length of any sector of the circle

Enghraifft / Example

Chwarter cylch = 90° Radiws = 5cmQuarter circle = 90° Radius = 5cm

241 rA

5cm

rC 241

241 5

2 63.19 cm

5241

cm 85.7

ARWYNEBEDD SECTOR A HYD ARCAREA OF SECTOR AND ARC LENGTH

Mae modd canfod arwynebedd a hyd arc unrhyw sector o gylchIt’s possible to find the area and arc length of any sector of the circle

Enghraifft / Example

Hanner cylch = 180° Radiws = 7.2cmHalf of a circle = 180° Radius = 7.2cm

221 rA

7.2cm

rC 221

221 2.7

2 43.81 cm

2.7221

cm 62.22

YMARFERION / EXERCISES

Cyfrifwch arwynebedd a hyd arc y canlynolCalculate the area and arc length of the following

5cm3.5cm 7.8cm

2.3cm

4.9cm

2.3cm 9.5cm 8.8cm

7.1cm 9.9cm