Question

Fine the value of x in this screenshot

Answer 1

x = 125º

Explanation:

Angles in a triangle add to 180º so:

180 - 42 - 83 = 180 - 125 = 55º

Angles on a straight line also add to 180º so to find x:

180 - 55 = 125º

x = 125º

Hope this helps.

Answer 2

The Exterior Angle Theorem

The exterior angle theorem states that one exterior angle of a triangle will always be equal to the sum of the two opposite interior angles.

Solving the Question

x is an exterior angle of the triangle.

We are given two interior angles in the triangle. These are opposite of x.

According to the exterior angle theorem, we can solve for x by adding these two angles:

• 42 + 83 = 125

Answer

x = 125