Pythagorean theoremThe rule that in a right triangle, the squares of the two shorter sides add up to the square of the longest side: a² + b² = c².
You’ll leave with these skills
01Find a circle’s circumference and area from its radius or diameterHalve the diameter to get the radius, then put the radius into the circumference and area formulas.
02Read a circle’s center and radius from its equationFirst write the circle as (x−h)²+(y−k)²=r². Its center is (h,k), and its radius is the positive square root of r². Read those values from this form, rather than from an expanded equation.
03Find the length of an arc or the area of a sectorPut the central angle over 360 degrees, then multiply that fraction by the circumference or the area.
04Find the center and radius when a circle’s equation is multiplied outComplete the square for the x-terms and the y-terms to rewrite the equation with squared parentheses that show the center and radius.
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71Math
40Reading
24Grammar
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