Download (4.1) Classifying Triangles (4.2) Angles of Triangles

October 28, 2016
(4.1) Classifying Triangles
(4.2) Angles of Triangles
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HW:
(Due Monday)
(4.1) Pg.242: 40-43, 49, 51, 56-64
(4.2) Pg.251: 21, 24-29, 38, 39, 44, 47, 49
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a
c
b
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4
3
2
1
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October 28, 2016
(4.1) Classifying Triangles
Explain what each classification means.
Angles:
Sides:
acute:
scalene:
right:
isosceles:
obtuse:
equilateral:
equiangular:
Converse of the Pythagorean Theorem:
(a, b, and c are side lengths of a triangle and c is the longest side)
If c2 = a2 + b2
then the triangle is right.
If c2 > a2 + b2
then the triangle is obtuse.
If c2 < a2 + b2
then the triangle is acute.
October 28, 2016
1. Classify the triangle by its sides and angles. Show all work.
A(7,6), B(5,3), C(9,1)
_____________________
October 28, 2016
Triangle Angle-Sum Theorem:
The sum of the measures of the angles of a triangle is 180o.
Complete the proof of the Triangle Angle-Sum Theorem.
2.
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3. Find the measures of the sides of the isosceles triangle with base KL.
L
KM = _____
x+6
K
4.
4x-13
12-x
M
LM = _____
KL = _____
1 = _____
2 = _____
3 = _____
4 = _____
5 = _____
October 28, 2016
Exterior Angle Theorem:
The exterior angle of triangle is equal to the sum of the two remote interior
angles.
Complete the Proof of the Exterior Angle Theorem.
Statements
Reasons
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5.