An obtuse triangle has one angle more than 90 degrees and two others less than 90s degrees.
\(180^{\circ} = 30^{\circ} + 40^{\circ} + x\)What is the one angle of an triangle, when the other ones are 40 and 30 degrees?
\(180^{\circ} = 70^{\circ} + x\)
\(180^{\circ} - 70^{\circ} = 70^{\circ} - 70^{\circ} + x\)
\(110^{\circ} = x\)
The triangle has one angle more than \(90^{\circ}\), and two that are less, so the triangle is obtuse.
