document.write( "Question 177536: 4. A triangle has two unknown angles A and B. If A is three times the size of B, and C = 39° 40’ 32” , find the magnitudes of A and B. \n" ); document.write( "
Algebra.Com's Answer #132546 by gonzo(654)\"\" \"About 
You can put this solution on YOUR website!
C = 39 degrees 40 minutes 32 seconds
\n" ); document.write( "32 seconds = 32/60 minutes = 32/60/60 degrees
\n" ); document.write( "40 minutes = 40/60 degrees
\n" ); document.write( "add those two together to get:
\n" ); document.write( "39.675555555..... degrees.
\n" ); document.write( "sum of angles of a triangle is 180.
\n" ); document.write( "180 - C = A + B = 180 - 39.6755555.... = 140.3244444...... degrees
\n" ); document.write( "A is 3 * B, so A + B is the same as B + 3*B = 4*B = 140.3244444..... degrees
\n" ); document.write( "this means that B = 140.324444...../4 = 35.0811111..... degrees
\n" ); document.write( "this means that A = 3*B = 105.2433333..... degrees
\n" ); document.write( "---
\n" ); document.write( "if we round to the nearest thousandth of a degree, we get:
\n" ); document.write( "C = 39.676 degrees
\n" ); document.write( "A = 105.243 degrees
\n" ); document.write( "B = 35.081 degrees
\n" ); document.write( "sum of 39.676 + 105.243 + 35.081 = 180 degrees.
\n" ); document.write( "---
\n" ); document.write( "A is 3 * B means that 3* 35.081 = 105.243 means that 105.243 = 105.243 means that this statement (A = 3*B) is true.
\n" ); document.write( "---
\n" ); document.write( "the magnitudes are in decimals.
\n" ); document.write( "to convert back to degrees, minutes, and seconds, you need to convert the decimal portion to minutes and seconds.
\n" ); document.write( "do this as follows:
\n" ); document.write( "take the fractional part and multiply by 3600.
\n" ); document.write( "this gets you seconds.
\n" ); document.write( "divide those seconds by 60 to get minutes.
\n" ); document.write( "that would be the integer part of the division.
\n" ); document.write( "take the fractional part of the minutes and multiply by 60 to get the remaining seconds.
\n" ); document.write( "---
\n" ); document.write( "to do this, use the unrounded answer, not the rounded answer, since the rounding will introduce some error in the result.
\n" ); document.write( "example:
\n" ); document.write( "C = 39.676 degrees
\n" ); document.write( ".676 * 3600 = 2433.6 seconds
\n" ); document.write( "2433.6 / 60 = 40.56 minutes
\n" ); document.write( "number of minutes is 40
\n" ); document.write( "number of seconds is .56 * 60 = 33.6 = 34 seconds
\n" ); document.write( "we know that the number of seconds is 32 because that was given.
\n" ); document.write( "the rounding introduced the error.
\n" ); document.write( "---
\n" ); document.write( "go back and do it again with the unrounded value this time.
\n" ); document.write( "C = 39.675555555.... degrees
\n" ); document.write( "use .675555555.... * 3600 to get seconds (maximum digits the calculator has should do).
\n" ); document.write( "you get 2431.99999999.... seconds
\n" ); document.write( "divide that by 60 to get:
\n" ); document.write( "40.5333333...... minutes
\n" ); document.write( "multiply .5333333..... * 60 to get:
\n" ); document.write( "31.999999998 seconds
\n" ); document.write( "your answer is:
\n" ); document.write( "C = 39 degrees 40 minutes 32 seconds which agrees with the original value provided.
\n" ); document.write( "---
\n" ); document.write( "do the same for A and B.
\n" ); document.write( "---
\n" ); document.write( "A = 105.2433333..... degrees
\n" ); document.write( ".2433333.... * 3600 = 875.99999999.... seconds
\n" ); document.write( ".875.9999999.... / 60 = 14.6 minutes
\n" ); document.write( ".6 * 60 = 36 seconds
\n" ); document.write( "A = 105 degrees 14 minutes 36 seconds
\n" ); document.write( "---
\n" ); document.write( "B = 35.0811111..... degrees
\n" ); document.write( ".0811111.... * 3600 = 292 seconds
\n" ); document.write( "292 / 60 = 4.866666666.... minutes
\n" ); document.write( ".866666666... * 60 = 52 seconds
\n" ); document.write( "B = 35 degrees 4 minutes 52 seconds
\n" ); document.write( "---
\n" ); document.write( "you have:
\n" ); document.write( "A = 105 degrees 14 minutes 36 seconds
\n" ); document.write( "B = 35 degrees 4 minutes 52 seconds
\n" ); document.write( "C = 39 degrees 40 minutes 32 seconds
\n" ); document.write( "----
\n" ); document.write( "add these together to get:
\n" ); document.write( "179 degrees 58 minutes 120 seconds
\n" ); document.write( "this adds up to 180 degrees so the conversion from decimals to minutes and seconds is good.
\n" ); document.write( "---
\n" ); document.write( "your answer is:
\n" ); document.write( "A = 105 degrees 14 minutes 36 seconds
\n" ); document.write( "B = 35 degrees 4 minutes 52 seconds
\n" ); document.write( "---\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );