Geometry-Ch. 3-Vocab

Question 1

sketch

Answer 1

make a freehand drawing of the figure without tools

Question 2

draw

Answer 2

carefully use geometry tools to measure and draw

Question 3

construct

Answer 3

use tools without measurements to construct a figure; there will always be inaccuracy in human measurement

Question 4

segment bisector

Answer 4

line, ray, or segment that passes through the mid midpoint of a segment

Question 5

perpendicular

Answer 5

segment that is perpendicular to the segment

Question 6

median

Answer 6

segment connecting a vertex to the midpoint of the opposite side in a triangle

Question 7

midsegment

Answer 7

a segment that connects the midpoints of two sides of a triangle

Question 8

converse

Answer 8

statement created by switching the if and then parts of a theorem

Question 9

altitude

Answer 9

a perpendicular segment in a triangle from a vertex to the opposite side; height of the triangle; always three per triangle.

Question 10

transversal

Answer 10

line that intersects two other separate lines.

Question 11

alternate interior angles

Answer 11

between two lines intersecting a transversal but on opposite sides of the transversal; equal when two of the lines are parallel

Question 12

alternate exterior angles

Answer 12

on opposite sides of the transversal and outside the two lines it intersects; equal when two of the lines are parallel

Question 13

co-interior angles

Answer 13

two angles on the same side of a transversal and both are interior; supplementary when two of the lines are parallel

Question 14

point of concurrency

Answer 14

point where three or more lines intersect

Question 15

incenter

Answer 15

point of concurrency for angle bisectors of triangle; think INcenter-> INGLES-> anGLES; equidistant from all three sides

Question 16

circumcenter

Answer 16

point of concurrency for perpendicular bisectors of triangle; think CIRcumcenter-> CIRCULAR-> perpendiCULARs; equidistant from vertices

Question 17

orthocenter

Answer 17

point of concurrency for altitudes of triangle; think ORTHOdontists ALTer teeth; ORTHOcenter- ALTitudes of triangle

Question 18

circumscribed

Answer 18

when a figure encloses another and the inside vertices fall on the outside figure

Question 19

inscribed

Answer 19

when a figure is inside of another and its vertices fall on the outside figure

Question 20

centroid

Answer 20

point of concurrency for medians of a triangle; divides medians into ratios of 2:1; center of a triangle’s mass