We encounter similar difficulties when we substitute rectangles for triangles in this configuration.

Important geometric figures, that are triangle, square, rectangle, circle, parallelogram and trapeze.

The opposite sides of a rectangle are parallel.

A square is one type of rectangle, and a rectangle is one type of parallelogram.

A square is always a rectangle, but a rectangle is not always a square.

A rectangle has four right angles.

The Japanese flag is a white rectangle with a red circle in the centre representing the sun.

A square is both a rectangle and a rhombus.

The area of a triangle is half of the area of the rectangle with equivalent base and height.

Some important geometric shapes are the triangle, the square, the rectangle, the circle, the parallelogram and the trapezium.