Interior angles in a triangle sum to a half turn (180˚). Quadrilaterals close quadrilateralA polygon with four straight sides. have four sides and four angles. Interior angles in a quadrilateral ...

Now, more than 122 years after it was first proposed, Kamata and two other mathematicians have finally proved that a solution ...

Many children's concept of a triangle is limited to the familiar equilateral triangle with a horizontal base. In this lesson, students will explore and identify a variety of triangular shapes using ...

Mathematicians struggled to find the fewest number of pieces needed to cut an equilateral triangle and rearrange it into a perfect square. The problem, known as “Dudeney’s dissection” or the ...