16.6 Circles p.368-369

I. Circle is all the points that are the same distance from a center point – this means every point in a circle is the same distance from the center.
II. Lines through a circle: labeled the same way as line segments – with a line above the two letters
A. Radius: a line segment with one endpoint at the center and the other endpoint on the circle
B. Chord: Line segment with both endpoints on the circle
a. Diameter: a chord that goes through the center of the circle
i. A diameter is twice the length of the radius
ii. A diameter is the longest chord that can be made in a circle

Here is an explanation on how to use a compass from mathsteacher.com

16.3 Find a Pattern p.360-361

I. Regular polygon: polygon in which all sides are congruent and all angles are congruent
II. Diagonal of a polygon: a line segment that joings two nonadjacent vertices of the polygon
III. The measure of each angle in a regular polygon with n sides is found using this following equation:

16.2 Triangles - ACTIVITY

• Use a straight edge to draw an example of each of the following
a. Triangles classified by their ANGLES
i. Right angle
ii. Acute angle
iii. Obtuse angle
b. Triangles classified by their SIDES
i. Scalene triangle
ii. Isosceles triangle
iii. Equilateral triangle
• Label the length or angle measures and write a written explanation for each triangle to show why it is different from the others and classified like it is. Use the example as a guide.

16.2 Triangles (p.356-357)

I. ALL TRIANGLES HAVE INTERIOR ANGLES THAT ADD UP TO 180 degrees
II. Naming Triangles by their ANGLES
A. A. Acute triangle: a triangle with all angles less than 90 degrees
B. B. Obtuse triangle: a triangle with one angle greater than 90 degrees
C. C. Right triangle: a triangle with one right angle

III. Naming Triangles by their sides
A. Equilateral triangle: a triangle with three congruent sides
B. Isosceles triangle: a triangle with exactly two congruent sides
C. Scalene triangle: a triangle with no congruent sides

Check out this helpful link from math.com for pictures and more explanation about each of these types of triangles

16.1 Polygons p.354-355

I. Polygon: Poly- =many, in this case 3 or more; -gon = sides

A. A closed plane figure (2-D) with straight sides that are connected line segments

B. We can use triangles to figure out the amount of total degrees for interior angles – all triangeles= 180 degrees total

C. Decagon: a polygon with ten sides, angles, and vertices

D. n-gon: a polygon with n sides, angles, and vertices

II. Vertex: a point where two sides of a polygon meet