Geometry Unit Three

Question 1

Triangle angle theorem

Answer 1

the sum of the measures of the 3 angles of a triangle is 180

Question 2

exterior angle

Answer 2

an angle that is adjacent to and supp. to an int angle of the polygon

Question 3

exterior angle theorem

Answer 3

the measure of an exterior angle of a triangle is equal to the sum of the measures of the remote interior angles

Question 4

midline theorem

Answer 4

a segment joining the midpoints of two sides of a triangle is parallel to the third side, and its length is half the length of the third side

Question 5

congruent figures

Answer 5

all pairs of corresponding parts (3 angles and 3 sides) are congruent

Question 6

reflexive property

Answer 6

any segment or angle is congruent to itself

Question 7

sss postulate

Answer 7

if there exists a correspondence between the vertices of two triangles such that three sides of one triangle are congruent to the corresponding sides of the other triangle, the two triangles are congruent

Question 8

sas postulate

Answer 8

if there exists a correspondence between the vertices of two triangles such that two sides and the included angle of one triangle are congruent to the corresponding parts of the other triangle, the two triangles are congruent

Question 9

asa postulate

Answer 9

if there exists a correspondence between the vertices of two triangles such that two angles and the included side of one triangle are congruent to the corresponding parts of the other triangle, the tow triangles are congruent

Question 10

third angle theorem

Answer 10

if two angles of one triangle are congruent to two angles of a second triangle, then the third angles are congruent

Question 11

aas postulate

Answer 11

if there exists a correspondence between the vertices of two triangles such that two angles and a nonincluded side of one are congruent to the corresponding parts of the other, then the triangles are congruent

Question 12

cpctc

Answer 12

corresponding parts of congruent triangles and congruent

Question 13

center of circle

Answer 13

same distance from every point on the circle

Question 14

radius

Answer 14

line from on the circle to the center

Question 15

area of circle

Answer 15

pi r sqared

Question 16

circumference

Answer 16

2 pi r

Question 17

radii theorem

Answer 17

all radii of a circle are congruent

Question 18

median2

Answer 18

• line segment drawn from any vertex of a triangle to the midpoint of the opposite side
• every triangle has 3 medians

Question 19

altitudes2

Answer 19

• line segment drawn from any vertex of the triangle to the opposite side that is perpendicular to that side
• every triangle has 3 alts, sometimes not all in triangle

Question 20

auxiliary lines

Answer 20

line introduced into a diagram for the purpose of clarifying a proof

Question 21

aux line postulate

Answer 21

two points determine a line

Question 22

scalene triangle

Answer 22

no two sides are congruent

Question 23

isosceles triangle

Answer 23

2 sides are congruent

Question 24

base

Answer 24

non congruent side of isosceles triangle

Question 25

legs (isosceles)

Answer 25

2 congruent sides of isosceles triangle

Question 26

base angles

Answer 26

angles made by the legs intersecting base of isosceles triangle

Question 27

vertex angles

Answer 27

angle made by the leg intersecting other leg of isosceles triangle

Question 28

equilateral triangle

Answer 28

all sides are congruent

Question 29

equiangular triangle

Answer 29

all angles are congruent

Question 30

acute triangle

Answer 30

all angles are acute

Question 31

right triangle

Answer 31

1 of the angles is a right angle

Question 32

hypotenuse

Answer 32

side opposite right angle

Question 33

legs (right)

Answer 33

sides that for the right angle

Question 34

obtuse triangle

Answer 34

1 of the angles is an obtuse angle

Question 35

angle side theorem3

Answer 35

• if two sides of a triangle are congruent, the angles opposite the sides are congruent
• if two angles of a triangle are congruent, the sides opposite the angles are congruent
• inverses are true

Question 36

ways to prove triangle is isosceles2

Answer 36

• 2 sides are congruent

- 2 angles are congruent

Question 37

hl postulate

Answer 37

if there exists a correspondence between the vertices of two right triangles such that the hypotenuse and a leg of one triangle are congruent to the corresponding parts of the other triangle, the two triangles are congruent

Question 38

right-angle theorem

Answer 38

if two angles are both supplementary and congruent, then they are right angles