document.write( "Question 169678This question is from textbook Geometry for enjoyment and challegne
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document.write( ": The measure of one angle of a parallelogram is 40 more than 3 times another. Find the measure of each angle. \n" );
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Algebra.Com's Answer #125089 by gonzo(654)![]() ![]() ![]() You can put this solution on YOUR website! in a parallelogram, the opposite angles are equal to each other. \n" ); document.write( "the sum of the angles in a parallelogram is 360. \n" ); document.write( "----- \n" ); document.write( "if the parallelogram is labeled ABCD, then angle A is equal to angle C because they are opposite each other, and angle B is equal to angle D because they are opposite to each other. \n" ); document.write( "----- \n" ); document.write( "the labeling of the parallelogram would be: \n" ); document.write( "A is lower left corner \n" ); document.write( "B is upper left corner \n" ); document.write( "C is upper right corner \n" ); document.write( "D is lower right corner \n" ); document.write( "----- \n" ); document.write( "assume A and C are the smaller angles. \n" ); document.write( "assume B and D are the larger angles. \n" ); document.write( "the parallelogram will be tilting to the right so that corner B is to the right of corner A. \n" ); document.write( "----- \n" ); document.write( "problem states that the larger angle is 3 times the smaller angle plus 40 degrees. \n" ); document.write( "since B is the larger angle and A is the smaller angle, that means that: \n" ); document.write( "B = 3*A + 40 \n" ); document.write( "----- \n" ); document.write( "since the sum of the angles in a parallelogram = 360 degrees then angle A + B + C + D = 360. \n" ); document.write( "since angle A = angle C, and angle B = angle D, this can be rewritten as 2*A + 2*B = 360 degrees by substituting A for C and B for D. \n" ); document.write( "----- \n" ); document.write( "equation you start out with is: \n" ); document.write( "2*A + 2*B = 360 \n" ); document.write( "----- \n" ); document.write( "you know that B = 3*A + 40 so you can substitute in equation. \n" ); document.write( "2*A + 2*B = 360 becomes: \n" ); document.write( "2*A + 2*(3*A+40) = 360 \n" ); document.write( "simplify: \n" ); document.write( "2*A + 2*3*A + 2*40 = 360 \n" ); document.write( "2*A + 6*A + 80 = 360 \n" ); document.write( "8*A + 80 = 360 \n" ); document.write( "subtract 80 from both sides of equation: \n" ); document.write( "8*A = 360 - 80 \n" ); document.write( "8*A = 280 \n" ); document.write( "divide both sides of equation by 8: \n" ); document.write( "A = 280 / 8 \n" ); document.write( "A = 35 \n" ); document.write( "----- \n" ); document.write( "angle A is 35 degrees. \n" ); document.write( "angle B is 3 * 35 + 40 \n" ); document.write( "angle B is 145 degrees. \n" ); document.write( "----- \n" ); document.write( "angle A and angle B = 180 degrees. \n" ); document.write( "2 * angle A and 2 * angle B = 360 degrees. \n" ); document.write( "this checks out with the sum of the angles of a parallelogram so the angles are good. \n" ); document.write( "answer is: \n" ); document.write( "smaller angle is 35 degrees. \n" ); document.write( "larger angle is 145 degrees. \n" ); document.write( "----- \n" ); document.write( " \n" ); document.write( " |