Presentation on theme: "Angles and Triangles p.551 D E F"— Presentation transcript:
1 . . 9.5 Angles and Triangles p.551 D E F Name the angle in five different ways.Angle DEF, angle FED,DEF, FED, or E
2 . . P R Q Name the angle in five different ways. Angle PQR, angle RQP, PQR, RQP, or Q
3 . . . Classifying Angles p.553 Right angle: An angle whose measure is 90o.Straight angle:An angle whose measure is 180o....CDE
4 Acute angle:An angle whose measure is greaterthan 0o and less than 90o.Obtuse angle:An angle whose measure isgreater than 90o and less than 180o.
5 Classify the angles as right, straight, acute or obtuse. Right angle...Straight angleCDEObtuse AngleAcute angle
6 Complementary Angles p. 554 Two angles are complementary if the sum of their measures is 90o. Each angle is called a complement of the other.Find the measure of a complement of the angle.15o45o18.104.22.168o75o45o18o
7 Supplementary Angles p. 555 Two angles are supplementary if the sum of their measures is 180o. Each angle is called a supplement of the other.Find the supplement of the angle given.1.38oo3. 90o142o23o90o
8 Triangles p. 555A triangle is a polygon made up of three segments, or sides. A triangle with vertices A, B, and C can be named ABC.ICFABEDGH
9 Types of Triangles p. 556 All sides are the same length. Equilateral triangle -Isosceles triangle –Scalene triangle –Two or more sides are the same length.All sides are of different lengths.
10 Types of Triangles p. 556 Right triangle – Obtuse triangle – Acute triangle –One angle is a right angle.One angle is an obtuse angle.All three angles are acute.
11 Sum of the Angle Measures of a Triangle In any triangle ABC, the sum of the measuresof the angles is 180o.Find the measure of angle A.Bx + 65o + 24o = 180o65ox + 89o = 180ox24ox = 180o – 89oCAx = 91o