30 terms

# GR6 Perimeter, Area, Circles, Angles and Triangles

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perimeter
the distance around a polygon
polygon
a closed figure formed by 3 or more line segments that intersect only at their endpoints
regular polygon
a polygon with equal sides
area
the number of square units needed to cover a given surface
parallelogram
a quadrilateral with 2 pairs of parallel sides
rectangle
a parallelogram with four right angles
triangle
a 3-sided polygon
center
the point inside a circle that is the same distance from all points on the circle
chord
a line segment with both endpoints on the circle
circle
the set of all points in a plane that are the same distance from a given point called the center
circumference
the distance around a circle
diameter
a line segment that passes through the center of a circle and has endpoints on the circle, or the length of that segment
pi (n)
the ratio of the circumference of a circle to the length of its diameter; π ≈ 3.14 or
a line segment with one endpoint at the center of a circle and the other endpoint on the circle, or the length of that segment
area
the measurement inside the circle
circumference
the measurement around the outside of a circle
pi
the ratio of the circumference of a circle to the length of its diameter; π ≈ 3.14 or 22/7
acute angle
measures less than 90°
acute triangle
a triangle with only acute angles
angle
two rays meet at an endpoint
complementary angle
two angles whose measures have a sum of 90°
equilateral triangle
a triangle whose all sides are equal
isosceles triangle
a triangle with at least two congruent sides
obtuse angle
measures more than 90°
obtuse triangle
a triangle with one obtuse angle
right angle
measures exactly 90°
right triangle
a triangle with one right angle
scalene triangle
a triangle with no congruent sides
straight angle
measures exactly 180°
supplementary angle
two angles whose measures have a sum of 180°