document.write( "Question 1002024: How can i explain how triangles are similar and how do i solve for missing lengths \n" ); document.write( "
Algebra.Com's Answer #619050 by MathLover1(20850)\"\" \"About 
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\n" ); document.write( "\n" ); document.write( "Two triangles are \"similar\" if they have:\r
\n" ); document.write( "\n" ); document.write( " all their angles equal
\n" ); document.write( " corresponding sides are in the same ratio\r
\n" ); document.write( "\n" ); document.write( "But we don't need to know all three sides and all three angles; two or three out of the six is usually enough.\r
\n" ); document.write( "\n" ); document.write( "There are three ways to find if two triangles are similar:
\n" ); document.write( "\"+AA\", \"SAS\" and \"SSS\"\r
\n" ); document.write( "\n" ); document.write( "\"AA\" stands for \"angle, angle\" and means that the triangles have two of their angles equal (could also be called \"AAA\" because when two angles are equal, all three angles must be equal). \r
\n" ); document.write( "\n" ); document.write( "If two of their angles are equal, then the third angle must also be equal, because angles of a triangle always add to make \"180\"°.\r
\n" ); document.write( "\n" ); document.write( "example: if one angle is \"72\"° and second angle is \"35\"°, the third
\n" ); document.write( "will be \"180-%2872+%2B+35%29+=+73\"°\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " \"SAS\" stands for \"side, angle, side\" and means that we have two triangles where:\r
\n" ); document.write( "\n" ); document.write( " the ratio between two sides is the same as the ratio between another two sides
\n" ); document.write( " and we we also know the included angles are equal\r
\n" ); document.write( "\n" ); document.write( "If two triangles have two pairs of sides in the same ratio and the included angles are also equal, then the triangles are similar.\r
\n" ); document.write( "\n" ); document.write( "example:\r
\n" ); document.write( "\n" ); document.write( " one pair of sides is in the ratio of \"21+%3A+14+=+3+%3A+2\"
\n" ); document.write( " another pair of sides is in the ratio of \"15+%3A+10+=+3+%3A+2\"
\n" ); document.write( " there is a matching angle of \"75\"° in between them\r
\n" ); document.write( "\n" ); document.write( "So there is enough information to tell us that the two triangles are similar.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " \"SSS\" stands for \"side, side, side\" and means that we have two triangles with all three pairs of corresponding sides in the same ratio.\r
\n" ); document.write( "\n" ); document.write( "If two triangles have three pairs of sides in the \"same\" \"ratio\", then the triangles are similar.\r
\n" ); document.write( "\n" ); document.write( "example:
\n" ); document.write( " the ratios of sides are:\r
\n" ); document.write( "\n" ); document.write( " \"a+%3A+x+=+6+%3A+7.5+=+12+%3A+15+=+4+%3A+5\"
\n" ); document.write( " \"b+%3A+y+=+8+%3A+10+=+4+%3A+5\"
\n" ); document.write( " \"c+%3A+z+=+4+%3A+5\"
\n" ); document.write( "These ratios are \"all\" \"equal\", so the two triangles are similar.
\n" ); document.write( "Since the ratios of the lengths of corresponding sides of similar figures are equal, then use this idea to find missing segment lengths in similar figures.\r
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