Question

Solve for x.
Round to the nearest tenth.

Answer 1

x = 65°

Explanation:

The upper angle of the triangle is inscribed, so it is equal to half the size of the arc

Let's call this angle α:

`\alpha = (100°)/(2) = 50°`

Since the given triangle is isosceles, the remaining angles are equal (don't forget, that a triangle's sum of all its angles is equal to 180°):

`2x + 50° = 180°`

`2x = 180° - 50°`

`2x = 130°`

Divide both sides of the equation by 2 to make x the subject:

`x = 65°`