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put this solution on YOUR website!WHEN 2 LINES CUT EACH OTHER ,WE GET 2 PAIRS OF VERTICALLY OPPOSITE ANGLES OR A TOTAL OF 4 ANGLES.AS VERTICALLY OPPOSITE ANGLES ARE EQUAL ,IF ONE ANGLE IS 28 THEN THE VERICALLY OPPOSITE ANGLE IS ALSO 28.NOW SINCE TWO OTHER LINES ARE PARALLEL TO ONE OF THESE,LET US LOOK AT ONE PAIR OF PARALLEL LINES.IN THAT PAIR IF IT IS CUT BY A LINE USUALLY CALLED TRANSVERSAL,WE WILL HAVE 2*4=8 ANGLES OF WHICH CORRESPONDING TO THE ABOVE 2 ANGLES OF 28 DEGREES WE HAVE 2 MORE OF 28 DEGREES ,BEING ALTERNATE/CORRESPONDING ANGLES . SO IN 3 PARALLEL LINES WE SHALL HAVE 6 ANGLES OF 28 DEGREES,OUT OF TOTAL 12 ANGLES