Hello radius Hello diameter Hello diameter Hello radii Slides: 24 Download presentation Hello radius! Hello diameter! Hello diameter! Hello radii! diameter is 4 cm! radius is 9 cm! diameter is 10 cm! semi + semi = whole circumference! diameter is 5 cm! semi x 4 = 2 circumferences! Area of a Circle Area : The space inside a shape! Recall. . • EVERY line from the centre of the circle to the circumference is a radius. L. O. To be able to discover the formula to find the Area of a Circle • Take a circle sheet each please! • Prepare: – a pair of scissors – 2 colours Step 1: Colour Half and Half Step 2: Cut the outline of the Circle Step 3: Cut out each sector Step 4: Re-arrange the pieces Alternate colours Alternate directions Okay…what does this shape look like? Yes, a Parallelogram! How do we find the Area of a Parallelogram? Area = Base x Height What’s our Base in this case? (outline of pink part) Base = ½ Circumference What’s the Height? Height = radius of circle How do we find the Circumference of a Circle? Circumference = 2 x π x radius =2πr Therefore…to find the Area of a Circle • Area of Circle = Area of Parallelogram = Base x Height = ½ x circumference x radius = ½x 2πrxr = πr² Area of Circle = π r ² Example 1 4 m What is the area of this circle? A= r² A= x 4 x 4 A = 50. 3 m² (1 d. p. ) Press Then x 4 = Example 2 ? 7 cm 14 cm What is the area of this circle? A= r² r = ½ x 14 = 7 cm A= Don’t forget! x 7 x 7 A = 153. 9 cm² (1 d. p. ) Press Then x 7 = Hello goodmorningPoint on circumference of circleIonic radius examplesHello hello hello how are youHello what's your nameCircle radius diameter chord circumferenceCircumference vocabularyRadius diameter chord secant tangentCircular measureHow to label radiusChord tangent radius diameterRadius and diameter of a circleFind the radius and diameter of each circleArea of a circleWhat is ionic radiiN kolApplications of cftHampaiden numerointiFossa olecraniVfi atomic radiiOssa longumArticularis cubitiRadius and ionization energyKode diagnosis corpus alienumLuksacija lakta