Download Polygons Notes w Pics 2015

Polygons
Triangle- Polygon with three sides and three angles. The sum of all interior angles of a triangle is 180˚.
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Classifying Triangles by Angles
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Acute triangle- A triangle in which all angles are acute (less that 90˚).
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Obtuse triangle- A triangle that has one obtuse angle (an angle greater than 90˚).
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Right triangle- A triangle that has a right angle (90˚).
Classifying Triangles by Side Lengths
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Isosceles triangle- A triangle that has at least two congruent sides and at least two
congruent angles.
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Equilateral triangle- An acute, isosceles triangle that has three congruent sides and three
congruent angles. An equilateral triangle is the only triangle that is ALWAYS regular.
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Scalene triangle- A triangle that does not have any congruent sides or congruent angles.
*For some triangles, you may combine names. Example- You may have right, isosceles triangle.
Quadrilateral- Polygon with four sides and four angles. Sum of all interior angles of a quadrilateral is
360˚.
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Kite- A quadrilateral that has two pairs of sides. Each pair is made up of adjacent sides that are
equal in length. The angles are equal where the pairs meet. Diagonals create perpendicular lines.
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Trapezoid- A quadrilateral that has at least one pair of parallel sides
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Parallelogram- A trapezoid with two pair of parallel and congruent sides, and opposite angles that
are congruent.
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Rectangle- A parallelogram with opposite sides that are congruent and parallel, and all interior
angles are right angles.
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Rhombus- A parallelogram that has four congruent sides and opposite angles are congruent.
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Square- A rhombus and rectangle. Squares have four congruent sides and the interior angles are
right angles. A square is the only quadrilateral that is ALWAYS regular.
**Polygons are considered regular if all sides are congruent and angles are congruent. **