Question

What is the measure of the straight angle?

Answer 1

Hint: A straight angle changes the direction to point the opposite way. Its measure is half of a revolution. It is also equal to two right angles.

Complete step-by-step solution -
An angle is defined as the amount of turn between two lines around their common point.
It is usually defined as a measure between two rays pointing in different directions but having the same vertex.
If the value of the angle is less than 90° it is called an acute angle. If the value of the angle is more than 90° it is called an obtuse angle.

When the rays are in a direction such that they form a straight line, the angle between them is called the straight angle.
Hence, we can also define the straight angle as the angle on a straight line. We know that the angle on a straight line is 180°.

 It is also equal to the angle covered in half a revolution, which is half of 360°.
\[\dfrac{{360^\circ }}{2} = 180^\circ \]
It is also equal to two times the right angle, which is two times 90°.
\[2 \times 90^\circ = 180^\circ \]
Hence, the measure of the straight angle is 180°.

Note: You may confuse yourself with the straight angle as 360°, since there are 180° each of either side of a straight line but that is wrong. We measure only one side.