A square marked at a vertex shows an angle that is exactly 90°. Image caption, The longest side of a triangle is opposite the largest angle. The shortest side of a triangle is opposite the ...

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 ...

(typical responses: size, all triangles, all coloured, all have three sides, all pointed the same way (orientation), all have angles). 2. After the initial discussion about the static triangle images, ...