Classification of Triangles Table of Contents v Objective

Classification of Triangles

Table of Contents v. Objective v. Review ØDefinition of a Triangle ØSamples of Triangular Objects ØTypes of angles ØCongruence of Line Segments v. According to Angle Measure v. According to Length of sides v. Review Questions

Objective: § At the end of the lesson, the students should be able to classify triangles.

Triangle It is a three sided polygon. A AC AB B BC C

Samples of Triangles that can be seen around us.

Acute Angle -It is an angle whose measure 0 is less than 90. B A 300 C <BAC which is an acute angle.

Right Angle -It is an angle whose 0 measure is equal to 90. 900

Obtuse Angle - It is an angle whose measure is greater than 900 but less than 1800. 1500

How can we say that two segments are Congruent ?

*Two are measuresegments of AB = measure of CD congruent if and A B only if they have C D equal length. 10 cm

CLASSIFICATION OF TRIANGLES According to angles According to sides

*ACUTE TRIANGLE -All the angles of the triangle are acute. K <J, <K, <L are all acute angles. 720 600 J 48 O L

RIGHT TRIANGLE N -An angle in a triangle is a right angle. HYPOTENUSE leg 900 M leg <M is a right angle. O The side opposite the right angle of a right triangle is called the hypotenuse. The other sides are called legs.

OBTUSE TRIANGLE - An angle in a triangle is an obtuse angle. Q <P is an obtuse angle. 1280 P R

SCALENE TRIANGLE -No two sides are congruent. B AB ~ = BC ~ = CA cm 6 c 4 m A 9 cm C

ISOSCELES TRIANGLE -two sides of the are congruent. E leg D The two equal sides of an isosceles triangle are called legs. The third side is called the base. leg base DE ~ = FE F

EQUILATERAL TRIANGLE -Three sides are congruent. H GH =~ HI ~ = GI G I

THE END!!! Rep orte db r o vad l a y: S Mr. : Jer o t em d e t y r o J p a e vier r R a z a l Sa