##### Across

**3.**A straight line that bisects an angle or a line segment**6.**A four-sided polygon**8.**A segment that connects two non adjacent vertices of a polygon**9.**The distance around a figure**12.**A quadrilateral in which all the angles have the same measures**13.**A simple quadrilateral with two pairs of parallel sides**15.**A transformation that slides a figure a given distance in a given direction**16.**A specific identifiable position in a continuum or series**18.**One of several parts that fit with others to make a whole**20.**The length of the closed curve of a circle.

##### Down

**1.**A three-sided polygon**2.**Have the same shape and size**4.**The act of changing in form or shape or appearance**5.**When Two angles add up to 180 degrees**7.**Two angles that add up to 90 degrees**10.**The points where two line segments come together**11.**Coplanar straight lines that do not intersect at any point**14.**Angle An angle that measures 90 degrees**17.**Being essentially comparable to something**19.**A figure formed by two line segments or rays with a common endpoint**21.**A plane curve with every point equidistant from the center