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Definition1

Title: Circles

Grade Lesson s2-l1

Explanation: The best way to understand SAT-4 is by looking at some definitions. Take turns and read each definition for easy understanding.

Definition

Topics → Definition Example1 Example2 Example3

Definition: Circles

A circle is a closed curve in which all points are equally distant from a fixed point called the center. The fixed distance from the center to any point on the circle is called the radius.

The standard equation of a circle in the Cartesian coordinate system with center (h, k) and radius r is given by:\$(x - h)^2 + (y-k)^2 = r^2\$, where (h, k) are the coordinates of the center of the circle.

$1$

Explanation:

In this image, h and k represent the center of the circle and r represents the radius.

Definition: Area of Sector

A sector of a circle is a portion of the circle enclosed by two radii and an arc between them. The area of a sector can be calculated using the formula: Area of Sector = \$("Central Angle"/360°) × πr^2\$, where Central Angle is the angle formed by the radii at the center of the circle (measured in degrees), and r is the radius of the circle.

$2$

Explanation:

In this image, the radius of 5 units and an arc length of 8 units, the sector of the circle defined by this arc length has an area of 20 square units,as determined by the formula A = \$(s×r / 2)\$.