A square has four right angles (90°). Each diagonal splits a corner into two angles of 45°. Note also that the diagonals cut each other in half at right angles. A rectangle has four right angles. The ...

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. What is a quadrilateral? A quadrilateral is a four-sided shape where each of the sides are straight and ...

The base and perpendicular height are at right angles. Showing that a parallelogram has the same area as a rectangle: Split the parallelogram into a right-angled triangle and a trapezium. Move the ...