Answer :
It’s a straight line. The “straight” angle is 180°.
So 180-42=138°
That means that a is a 138° angle.
So 180-42=138°
That means that a is a 138° angle.
The measure of the missing angle. 42 is a 138 degree angle as the angles is straight.
What is the straight angle?
A staright attitude is likewise known as 'flat attitude'. In the picture, OX and OY are the fingers of an attitude. The not unusualplace factor O wherein the rays meet is known as the vertex.
So 180 - 42 = 138 degree.That method that a is a 138 degree attitude.
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