Show:
Polygons
Angles
Symmetry
Angle Tools
Angles Cont.
100
Polygons are shapes formed by line segments so that each of the segments meets exactly two other segments, and all the points where the segments meet are endpoints of segments. Non-polygons have crossed lines, curved lines, and gaps between the lines.
What is the difference between a polygon and a non-polygon?
100
A pair of angles whose measures add to 90°.
What are complementary angles?
100
A shape has this if it can be rotated less than a full turn about its center point to a position where it looked exactly as it did before it was rotated.
What is rotational symmetry?
100
Align the baseline with the bottom line segment of the angle and see where the top line goes to the top of the protractor.
How do you measure an angle using a protractor?
100
An angle at a vertex of a polygon where the sides of the angle are one side of the polygon?
What is an exterior angle?
200
A regular polygon's sides and angles are all equal to each other. An irregular polygon has at least two sides with different lengths.
What is the difference between a regular polygon and an irregular polygon?
200
A pair of angles whose measures add to 180°.
What is a supplementary angle?
200
Two halves that are mirror images of each other.
What is reflectional symmetry?
200
Line one part of the angle ruler to the bottom line, and line the other part to the top line.
How do you measure angles using an angle ruler?
200
(n-2)x180
What is the formula for finding the measure of the interior angles of a regular polygon?
300
A concave polygon has at least one interior angle whose measure is greater than 180°. A convex polygon has all interior angles measuring less than 180°.
What is the difference between a concave polygon and a convex polygon?
300
Two angles that have a common vertex and a common side.
What are adjacent angles?
300
Draw a cross where the two lines meet at the vertex. Then, using your knowledge of right angles and straight angles, pinpoint the number that would be at that vertex.
How do you estimate the measure of an angle?
300
(n-2)x180-n
What is the formula for finding an angle sum?
400
Triangles, which have three sides; quadrilaterals, which have four side; pentagons, which have five sides; hexagons, which have six sides; heptagons, which have seven sides; octagons, which have eight sides; nonagons, which have nine sides; and decagons, which have ten sides.
What are the names of the first seven polygons?
400
Congruent angles that share a vertex.
What are vertical angles?
400
If one of the angles is listed, just multiply the angle by two, subtract it from 360, and divide the difference by two.
How do you identify angles on a diagram with a transversal?
500
The angle inside a polygon formed by two adjacent sides of the polygon.
What is an interior angle?