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(81) REGULAR POLYGON

What do we call a polygon in which all angles are congruent and all sides are congruent?

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(82) TRIANGLE

In what shape do all the interior angles add up to 180 degrees?

###
(83a) SCALENE (TRIANGLE)

What kind of triangle has no equal sides?

###
(83b) ISOSCELES (TRIANGLE)

What kind of triangle has two equal sides?

###
(83c) EQUILATERAL (TRIANGLE)

What kind of triangle has three equal sides?

###
(84a) ACUTE (TRIANGLE)

What do we call a triangle with all angles measuring less than 90 degrees?

###
(84b) OBTUSE (TRIANGLE)

What do we call a triangle containing one obtuse angle?

###
(84c) RIGHT (TRIANGLE)

What do we call a triangle containing one right angle?

###
(85) PARALLELOGRAM

What is a four-sided figure with two sets of parallel sides called?

###
(86) PERIMETER

What is the distance around the outside of a closed figure called?

###
(87) DIAMETER

What is a segment connecting two points on a circle and passing through its center called?

###
(88) RADIUS

What is the distance from the edge of a circle to its center called?

###
(89) CIRCUMFERENCE

What is the distance around a circle?

###
(90) C = π • d

What is the formula for finding the circumference of a circle?

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