A scalene triangle has 3 sides of different lengths and 3 unequal angles. An isosceles triangle has 2 sides of equal length. The dashes on the lines show they are equal in length. The angles at the ...

An obtuse angle is between \(90^\circ\) and \(180^\circ\). To estimate the size of an angle, try thinking in terms of counting in quarter turns, or right angles. For example, the angle in the ...

The Pythagorean theorem, a cornerstone of mathematics for millennia, provides a method for determining unknown sides in right-angled triangles using the formula a² + b² = c². Its applications extend ...