Types of Triangles And Angle Sum Theorems. Notation for sides. AB CB AC Angles ABC or B ...
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Transcript of Types of Triangles And Angle Sum Theorems. Notation for sides. AB CB AC Angles ABC or B ...
Types of TrianglesAnd Angle Sum Theorems
Notation for sides. AB CB AC Angles ABC or B Vertex angle Base angle Opposite side Opposite angle
A
B C
Equilateral Triangle : all sides and angles are congruent. ( Equiangular Triangle)
9
9
9
At least two sides and two angles are congruent.
10 10
4
Vertex
Base Angles
None of the sides or angles are congruent
8
11
4
m∠A + m∠B + m∠C = 180 degrees
A
B
C
Find the value of the unknown angle.
87 °44 °
x°
180 ° – 87 ° – 44 ° = Unknown angle X
= 49 °
X° + 87° + 44° = 180°
m∠ A = (2x – 3)° , m∠ B = (x + 5)° , and m∠ C = (x + 8)°
C B
A
Solution
m∠A + m∠B = m∠E The sum of the remote interior angles equal
the value of the exterior angle.
A B
E exterior angle
remote interior angle
56°
88°
E°
56° + 88° = the unknown exterior angle
= 144 degrees
All angles are congruent. They are each 60 degrees. (Equilateral Triangle)
60°
60°
60°
61°
38°
X° Y°
Z°
26°
180° – 38° – 61° = 81° X° 61° + 38° = 99° Y°
180° – 26° – 99° = 55° Z°
122 °
18 °
T° V° K°
R°
Solution
P°