Rational number because /An irrational number has endless non-repeating digits to the right of the decimal point.
Let X and Y be the digits.
If a two-digit number is written XY, then its value is 10x+y.
When the digits of the number are interchanged, it's YX, and its value is 10y+x.
The sum of the digits is 12.
The number formed by interchaning the digits is 54 more than the original number.

The digits X and Y are 3 and 9, so the original number is 39.
Step-by-step explanation:
Let x be the length of segment AB.
Then the length of segment BC is (2x - 4).
The length of segment AC is x.
We know that x + (2x - 4) + x = 52.
Therefore 4x - 4 = 52, 4x = 56, x = 14.
Hence the length of segment AB is 14.
It would be the last one to add up to 180 witch is a triangle or supplementary
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45 + 4 makes 49 if that counts