Answer:
x = 75°
Step-by-step explanation:
There are many Circle Geometry Rules. We will be using the following:
The angle at the centre of the circle is twice the angle at the circumference.
x = the angle opposite 285 - x.
This means that 360 - (285 - x) = 2x
360 - 285 + x = 2x
75 + x = 2x
We can simplify this by taking away x from both sides.
75 = x
We can check this by substituting x into the orginal equation.
360 - (285 - x) = 2x
360 - (285 - 75) = 2 * 75
360 - 210 = 2 * 75
150 = 2*75
150 = 150
