It can be shown, for example, that for masonry having a density of 3, water being 1, the figure of minimum section is a **right-angled** triangle, with the water against its vertical face; while for a greater density the water face must lean towards the water, and for a less density away from the water, so that the water may lie upon it.

- Diagram of **Right-Angled** cubic feet of water, acting g at one-third its depth above Triangle Dam.

By adopting **right-angled** reflectionprisms above the eyepiece he completely erected the image.

24, that he was the first person to describe a **right-angled** triangle in a circle.

When hardened in situ its shape is that of a **right-angled**, triangular prism showing five surfaces - superior, anterior, inferior, posterior and right lateral which represents the base of the prism.

(iii) **Right-angled** triangle: sides a and b, enclosing the right angle.

If the **right-angled** triangle abc, fig.

2-}-cos B It is readily shown that the latter gives the best approximation to 0; but, while the former requires for its application a knowledge of the trigonometrical ratios of only one angle (in other words, the ratios of the sides of only one **right-angled** triangle), the latter requires the same for two angles, 0 and 3B.

Within the focus of the object-glass is a **right-angled** prism of total reflection, which diverts the converging rays from the object-glass at right angles to the axis of the telescope, and permits the observing micrometer n to be mounted in the very convenient position shown in the figure.

To say, for instance, that the area of a **right-angled** triangle is half the area of the rectangle contained by the two sides, is not to say what the area is, but what it is the half of.