Chapter 4

Question 1

Equilateral triangle

Answer 1

Has three congruent sides

Question 2

Isosceles triangle

Answer 2

Has at least two congruent sides

Question 3

Scalene triangle

Answer 3

Has no sides congruent

Question 4

Congruent triangles

Answer 4

Two triangles are congruent if there is a correspondence between their angles and sides such that corresponding angles are congruent and corresponding sides are congruent .

Question 5

Acute triangle

Answer 5

Has three acute angles

Question 6

Equiangular triangle

Answer 6

If these angles are all congruent, then the triangle is also equiangular

Question 7

Right triangle

Answer 7

Has exactly one right angle

Question 8

Obtuse triangle

Answer 8

Has exactly one of obtuse angle

Question 9

Vertex

Answer 9

Point of intersection of two sides

Question 10

Adjacent side

Answer 10

Two sides that share a common vertex

Question 11

Opposite side

Answer 11

Any side opposite a given angle

Question 12

Right triangle- legs

Answer 12

The sides adjacent to the right angle

Question 13

Right triangle

Hypotenuse

Answer 13

The side opposite the right angle

Question 14

Isosceles triangle -legs

Answer 14

If it has only two congruent sides, then the two congruent sides are the legs

Question 15

Isosceles triangle

Base

Answer 15

The third side of the triangle

Question 16

Properties of congruent triangles

Answer 16

1. Every triangle is congruent to itself
2. If triangle ABC is congruent to triangle PQR, then triangle PQR is congruent to ABC
3. If triangle ABC = triangle PQR and triangle PQR = TUV, then triangle ABC = triangle TUV

Question 17

Interior angle

Answer 17

Angles formed by the sides of a figure, located in the interior of the figure

Question 18

Exterior angle

Answer 18

An angle that is adjacent to an interior angle (must form a linear pair)

•an angle that forms a linear pair with an interior angle

Question 19

Triangle sum Theorem

Answer 19

The sum of the measures of the interior angles of a triangle is 180°

Question 20

Third angles theorem

Answer 20

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

Question 21

The aCute angles of a right triangle…

Answer 21

Are complementary

Question 22

Exterior angles theorem

Answer 22

The measure of an exterior angle of a triangle is equal to the sum of the measures of the two remote (nonadjacent) interior angles.

Question 23

Exterior angles inequality theorem

Answer 23

Measure of an exterior angle of a triangle is greater than the measure of either the two remote (nonadjacent) inferior angles

Question 24

Postulate 17: side – side – side congruence postulate

Answer 24

If three sides of one triangle are congruent to three sides of a second triangle, then the triangles are congruent

Question 25

Postulate 18: side – angle – side congruence postulate

Answer 25

If two sides and the included angles of one triangle are congruent to two sides and the included angle of a second triangle, then the triangles are congruent

Question 26

Partial at 19: angle – side – angle congruence postulate

Answer 26

If two angles and the included side of one triangle are congruent to two angles and the included side of a second triangle, then the two angles are congruent.

Question 27

There are 4.7: angle – angle – side congruence theorem•••

Answer 27

If two angles and a non-included side of one triangle are congruent to two angles and the corresponding not included side of the second triangle, then the two triangles are congruent

Question 28

CPCTC

Answer 28

CP CTC is an abbreviation for corresponding parts of congruent triangles are congruent

Question 29

Base angles

Answer 29

The two angles that have the base as a part of one side are the base angles

Question 30

Base angles theorem

Answer 30

If two sides of a triangle are congruent, then the angles opposite them are congruent

Question 31

Base angles converse theorem

Answer 31

If two angles of a triangle are congruent, then the sides opposite them are congruent.

Question 32

Corollary of 4.8: if a triangle is equilateral,

Answer 32

Then it is also equiangular

Question 33

Corollary to theorem 4.9: if a triangle is equiangular,

Answer 33

Then it is also equilateral

Question 34

Hypotenuse – leg congruence theorem

Answer 34

If the hypotenuse and a leg of a right triangle are congruent to the hypotenuse and leg of a second triangle, then the two triangles are congruent