Classifying Triangles By Angles And Sides

Classifying Triangles by Angles and SidesName:GeometryLESSON4-1Acute TriangleRight Triangle Obtuse Triangle all acute anglesEquiangular Tri. one right angle60 6060one obtuse angleall anglesoClassify each triangle by its angle measures. Remember, there are 180 in every triangle.2.1.3. Classify: Classify:Classify:322719652562third angle third angle third angle Classify:Classify:Classify:Use the figure to classify each triangle by its angle measures.4. DFG 5. DEG %6. EFG' &

Classifying Triangles by SidesPage 2LESSON4-1Equilateral Triangle Isosceles TriangleScalene Triangle all sides congruentStep 1Step 2Find the value of x.QR RS4x 3x 5x 5at least two sidescongruentno sides congruent2Def. of segs.SubstitutionSimplify. X XUse substitution to find the length of a side.4x 4(5)Substitute 5 for x. 20Simplify.1Each side length of QRS is 20.3Classify each triangle by its side lengths.7. EGF is 8. DEF is%9. DFG is 'Find the side lengths of each triangle. X X 10.& 11. X X 2x - 7x 19Equation:x Side length X Equation:x Side lengths ,

Classifying TrianglesPage 3LESSON4-1Practice AMatch the letter of the figure to the correct vocabulary word in Exercises 1–4.1. right triangleA.B.C.D.2. obtuse triangle3. acute triangle4. equiangular triangleClassify each triangle by its angle measures as acute, equiangular, right, or obtuse.(Note: Give two classifications on # 7.)605.6.45 7.30 45 60 14 136 60 abcongruent sides.8. An isosceles triangle hastriangle has three congruent sides.9. A(n)triangle has no congruent sides.10. A(n)Classify each triangle by its side lengths as equilateral, isosceles, or scalene.(Note: Give two classifications on #13.)12.11.13.122.5aFind the side lengths of the triangle.Equation:x 2!x 14. AB #15AC bX 61715"BC 15. The New York City subway is known for its crowded cars. If all the seatsin a car are taken, passengers must stand and steady themselves withrailings or handholds. How many hand straps could have been madefrom 99 inches of steel?2114 in.14 in.5 in.

G.1.AClassifying TrianglesPage 4LESSON4-1Practice B Classify each triangle by its angle measures.(Note: Some triangles may belong to more than one class.)50 !100 "40 1. ABD2. ADC3. BCD#'(Classify each triangle by its side lengths.4.GIJ5.3X 0.47.2HIJ6.)6.9GHJ*0X 0.1X 1.41Equation:x PQ QR RP 8.32N 3 3–447N10N 21–451ST TU US 49. UseChelseaworksthe kitchentoofdrawPizzaTodayjob ofis toa rulerandina compassa Pro.trianglewithhersides3 cm, 4 cm, and 5 cm.6 cmof thecut pizzasmallsegment.triangles.Then,She usesa cuttingmachine,Firstdrawintoa 5-cmset yourcompassto 3 cm and make an arc from one end5.7 cmso everytrianglecomessetoutyourthe compasssame. Theshowsan an arc from the other5-cmsegment.Finally,to figure4 cm andmake4 cmend of the 5-cmexample. MarkShe hasbeenwheretold tothecutarcs3 pizzatrianglesfor everyguest.segment.the pointintersect.Connectthis pointto the ends of the 5-cm segment.There will be 250 guests. If the pizza comes insquares with 20-centimeter sides and she doesn’t waste anypizza, how many squares of pizza will Chelsea have to cut up? CM CM CM

Page 5 show work!Choose the best answer.‹ ›1. Which list shows all the segments on ACthat contain the point B ?ABCDABCDACAB ,AB ,AB ,BC,AC,AC ,BDAD ,AD ,BC, BDBC , BD , CD2. M is between R and S. If RM 21,RS 15x 3, and MS 9x 12.Equation:3. K is the midpoint of VW . If KV 3x andKW 5x 10.6. Two vertical angles are alsocomplementary. What is the measureof one of the two vertical angles?F 90 H 45 G 50 J 25 7. The area of a square is 16 square units.What is the perimeter?A 4 unitsC 16 unitsB 8 unitsD 32 units8. The midpoint of a segment is ( 8, 5). IfDraw andlabeldiagram.one endpointis (0,1),awhatis the otherendpoint?F ( 16, 9)H ( 4, 2)G (8, 3)J ( 4, 3)x RS MS 9. To the nearest tenth, what is the distanceDrawandandlabel( 3,a diagram.between (7, 4) 1)?A 5C 20.5B 10.4D 54.5Equation: 10.x WhichKV KW coordinatepair representstheimage of (9, 10) reflected over the4. Which appears to be an obtuse angle?x-axis?2F (9, 10)H ( 9, 10)4J (10, 9)G ( 9, 10)311. What is the next figure in the pattern?1F PQRG PSQ0H RJ PACBD5. Which two angles are supplementary to RLK?12. For which statement is the conversefalse?1F If Mary can swim, then she can swim02the crawl.,G If it is raining outside, then the temperature is above freezing.H If Greg has two children, then he hasone son and one daughter.andJ If Carolyn can stand up, then shecan walk.

LESSON 4-1 Equilateral Triangle Isosceles Triangle Scalene Triangle all sides congruent at least two sides congruent no sides congruent Step 1 Find the value of x. QR RS Def. of segs. 4x 3x 5 Substitution x 5 Simplify. Step 2 Use substitution to find the length of a side.