AreaofTrianglesandTrapezoids Name:Pre-Algebra Date:Chapter10–Lesson2Pre-Algebra Date:Chapter10–Lesson2

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AreaofTriangles Everyparallelogramcanbedividedinto2congruenttriangles.

TheareaofeachtriangleisHALFtheareaoftheparallelogram.Theformulaforareaofatriangleis:

𝐴∆ =12 𝑏ℎ

whereb=baseandh=heightTheheightisdefinedastheperpendiculardistancefromonevertexofthetriangletoitsoppositeside.

Example:Findtheareaofthistriangle:

𝐴 =

12 𝑏ℎ

𝐴 =12 14 5

𝐴 = 35 𝑠𝑞𝑢𝑎𝑟𝑒 𝑢𝑛𝑖𝑡𝑠

AreaofTrapezoids Theformulafortheareaofatrapezoidis:

𝐴!"#$ =12 ℎ (𝑏! + 𝑏!)

whereh=height𝑏!=lengthofoneofthebases𝑏!=lengthoftheotherbase

AreaofTrianglesandTrapezoids Name:Pre-Algebra Date:Chapter10–Lesson2Pre-Algebra Date:Chapter10–Lesson2

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Example:

𝐴 =

12ℎ (𝑏! + 𝑏!)

𝐴 =12 4 (10+ 6)

𝐴 =12 4 (16)

𝐴 = 32 𝑠𝑞𝑢𝑎𝑟𝑒 𝑢𝑛𝑖𝑡𝑠