Lady Belinda

Lady Belinda is an enthusiastic gardener. 
One of her gardens is oblong in shape, enclosed by a high holly hedge, and she is turning it into a rosary for the cultivation of some of her choicest roses. 
She wants to devote exactly half of the area of the garden to the flowers, in one large bed, and the other half to be a path going all round it of equal breadth throughout. 
Such a garden is shown in the diagram at the foot of the picture. 

How is she to mark out the garden under these simple conditions? 

She has only a tape, the length of the garden, to do it with, and, as the holly hedge is so thick and dense, she must make all her measurements inside. 

See answer

Math Genius