Presentation on theme: "8.5 Areas of Circles. What is ? Investigation: A Taste of p 332 = 3.14159265….. If C is the circumference and d is the diameter of a circle, then."— Presentation transcript:
8.5 Areas of Circles
What is ? Investigation: A Taste of p 332 = ….. If C is the circumference and d is the diameter of a circle, then there is a number such that C = _______. If d = 2r, where r is the radius, then C = _______. dd 2r2r
Area Investigation: Area Formula for Circles p 433 The area of a circle is given by the formula _______, where A is the area and r is the radius of the circle. A = r 2
8.6 Any Way You Slice It Cut my pie into four pieces – I don’t think I could eat eight. YOGI BERRA
Definitions Sector, segment, annulus
Find the area of the shaded sector The sector is 45⁰ and the radius is 20 cm.
Find the area of the shaded segment The radius is 6 cm and it is an isosceles right triangle.
The shaded area is 14π cm², and the radius is 6 cm, what is the measure of the central angle?