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Perimeter, Circumference, and Area. 1.7 Ms. Verdino. Review of Polygons. A polygon is a closed plane figure formed by three or more segments. Each segment is called a side. Each endpoint of the side is called the vertex. Names of Common Polygons. Key vocabulary for polygons.
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Perimeter, Circumference, and Area 1.7 Ms. Verdino
Review of Polygons • A polygon is a closed plane figure formed by three or more segments. • Each segment is called a side. • Each endpoint of the side is called the vertex.
Key vocabulary for polygons • A diagonal is a segment that connects two nonconsecutive vertices. • A convex polygon has no diagonal with points outside the polygon. • A concave polygon has at least one diagonal with points outside the polygon.
Perimeter, Circumference, and Area • The perimeterP of a polygon is the sum of the lengths of its sides. • The areaA of a polygon is the number of square units it encloses. • The circumferenceC is the enclosing boundary of a curved geometric figure.
Formulas Triangle Side length a,b,c Base b, and height h Area: Perimeter: Square Side length s. Area: Perimeter: Rectangle Base b and height h Area: Perimeter: Circle Radius r and diameter d Area: Circumference:
Finding the perimeter • You want to frame a picture that is 5 in by 7 in with a 1-in-wide frame. • What is the perimeter or the picture? • What is the perimeter of the outside edge of the frame?
Finding the circumference and area. • The diameter of a circle is 12 cm. What is the circumference and area of the circle in terms of pi?
Your turn The radius of the circle is 8 in. What is the circumference and area of the circle in terms of pi?
Area Addition Postulate The area of a region is the sum of the area of the nonoverlapping parts.