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Triangles

Terms in this set (16)

Polygon
Plane shapes with 3 or more sides which are all straight lines
Triangle
three sided polygon
Acute-angled triangle
triangle whose all three angles are less than ninety degrees
Right-angled triangle
triangle that contains one angle that equals ninety degrees.
Obtuse-angled triangle
triangle that contains one angle that is greater than ninety degrees
Scalene triangle
triangle that contains no sides equal in length
Isosceles triangle
Triangle that contains two sides that are equal in length.
Two base angles are also equal.
Vertex angle
the angle formed by the congruent sides or legs of an isosceles triangle
Base
the side opposite the vertex angle
Base angles
the angles formed by the congruent sides and the base of an isosceles triangle, base angles are equal in measure
Equilateral (equiangular) triangle
triangle in which all sides and all angles are congruent
Sum of all three angles in a triangle
180 degrees
Number of triangles you can make inside a quadrilateral by connecting one vertex with all others
2
Number of triangles you can make inside a pentagon by connecting one vertex with all others
3
Number of triangles you can make inside a hexagon by connecting one vertex with all others
4
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