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 ...

Big Idea – We can describe, measure, and compare spatial relationships. to build on students' knowledge of triangle and to develop students' reasoning with properties of triangle to develop students' ...

Do you think there’s a triangle whose angles measure 41, 76 and 63 degrees? At first, answering this may seem easy. From geometry class we know that the sum of the measures of the interior angles of a ...

Big Idea – We can describe, measure, and compare spatial relationships. to build on students' knowledge of triangle and to develop students' reasoning with properties of triangle to develop students' ...

We know all four shapes are the same before and after, but we assumed that the large right triangle also stayed the same size and shape. This assumption was our error! It turns out that the “before” ...

Interior angles in a triangle add up to 180˚. Triangles close triangleA polygon with three straight sides. have three sides, therefore they have three angles. Interior angles in a triangle sum to a ...