PROBLEM 1A
PROBLEM 2A
PROBLEM 3A
PROBLEM 4A
PROBLEM 1B
PROBLEM 4B
PROBLEM 2B
PROBLEM 3B
TRIANGLES AS POLYGONS: CLASSIFICATION
PRESENTATION CREATED BY SIMON PEREZ RHS. All rights reserved
Standards 4 and 5
REFLEXIVE, SYMMETRIC AND TRANSITIVE PROPERTIES
EXTERIOR ANGLE THEOREM
CPCTC
ANGLE SUM THEOREM
PROBLEM 5A PROBLEM 5B
STANDARD 4:Students prove basic theorems involving congruence and similarity.
ESTÁNDAR 4: Los estudiantes prueban teoremas que involucran congruencia y semejanza.
STANDARD 5:Students prove that triangles are congruent or similar, and they are able to use the concept of corresponding parts of congruent triangles.
ESTÁNDAR 5: Los estudiantes prueban que son triángulos congruentes o semejantes y son capaces de usar el concepto de partes correspondientes de triángulos congruentes.
These are examples of POLYGONS:
These are NOT POLYGONS:
A POLYGON is a closed figure in a plane which is made up of line segments, called sides, that intersect only at their endpoints, named vertices.
Standards 4 and 5
A TRIANGLE is a three-sided polygon
Standards 4 and 5
55°
64° 61°
21°
110° 49°
RIGHT TRIANGLE
ACUTE TRIANGLE
OBTUSE TRIANGLE
CLASSIFYING TRIANGLES BY ANGLESANGLES
STANDARDS 4 and 5
PRESENTATION CREATED BY SIMON PEREZ RHS. All rights reserved
Parts of a RIGHT TRIANGLE
Leg
Leg
HYPOTENUSE
Right Angle
A
Am =180°
B
Bm+
C
Cm+If and A = 90°m then
=180°Bm+ Cm+90°- 90° -90°
=90°Bm Cm+
Conclusion: In a right triangle, both non- right angles are acute and complementary!
What kind of angles are the non-right angles in a right triangle?
CLASSIFYING TRIANGLES BY SIDESSIDES
10
4
9 22 22
9
13 13
13
SCALENE TRIANGLE
ISOSCELES TRIANGLE
EQUILATERAL TRIANGLE
Standards 4 and 5
Sample Questions
Identify the triangles by their angles and their sides
A
CB D
Right Triangles
Obtuse Triangles
Isosceles Triangles
Name the type of triangles with the following characteristics
5x 6x-5
3x+10
Find the value of x to make the triangle equilateral.
XYZ has coordinates X(2,6) Y(4,-5) Z(-3,0). Classify the triangle by angles and sides.
