Chapter 4

Question 1

Triangle Sum Theorem

Corollary

Answer 1

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

he acute angles of a right
triangle are complementary

Question 2

Exterior Angle Theorem

Answer 2

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

Question 3

Third Angles Theorem

Answer 3

If two angles of one
triangle are congruent to two angles of
another triangle, then the third angles are
also congruent.

Question 4

Properties of Triangle Congruence

Answer 4

Triangle congruence is reflexive, symmetric,
and transitive.
Reflexive: For any n ABC, n ABC > n ABC.
Symmetric: If n ABC > nDEF, then
nDEF > n ABC.
Transitive: If n ABC > nDEF and
nDEF > nJKL, then
n ABC > nJKL. (p. 228)

Question 5

Hypotenuse-Leg (HL) Congruence
Theorem

Answer 5

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

Question 6

Angle-Angle-Side (AAS) Congruence
Theorem

Answer 6

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

Question 7

Base Angles Theorem

Answer 7

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

Question 8

Base Angles Corollary

Answer 8

If a triangle is equilateral, then it
is equiangular

Question 9

Converse of the Base Angles Theorem

Answer 9

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

Question 10

Converse of Base Angles Corollary

Answer 10

If a triangle is equiangular, then it
is equilateral