A triangle has one interior angle that has a measure 45°, another interior angle that has measure x°, and an exterior angle that has measure 85°, as shown in the diagram.

What is the value of x?

The adjacent angle to 85° is equal to 95°, since angles on a straight line add up to 180°.

Therefore, the interior angles of the triangle would be:

45°, 95°, and x°

45 + 95 + x = 180 {angles of a triangle add up to 180}

140 + x = 180 {combined like terms}

Therefore, the interior angles of the triangle would be:

45°, 95°, and x°

45 + 95 + x = 180 {angles of a triangle add up to 180}

140 + x = 180 {combined like terms}

**x = 40°**{subtracted 140 from each side}**- Algebra House**