The measure of the unknown angle is 70 degrees
In circle geometry, there is a theorem that states that the angle at the centre of a circle is twice the angle at the circumference
Given the following parameters;
Angle at the circumference = x
Angle at the centre = 140 degrees
Using the given theorem;
140 = 2x
Swap
2x = 140
x = 140/2
x = 70
Hence the measure of the unknown angle is 70 degrees
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