right-angled triangle BrE
right triangle AmE

Of these the first two, but not the last three, are right triangles.

For example, a right triangle may have angles that form simple relationships, such as 45-45-90.

The overall footprint on the 65,000 m2 site is of a right triangle.

That outlined by the right triangle became the study center.

If the ramp has to form a right triangle, what should its height be?

The area of the right triangle is where a and b are the legs.

The design is a space frame in the shape of a right triangle.

The small district is carved into the shape of a right triangle.

When looking on a map, the two spans and the south bank of the river form a right triangle.

Oh, yes - the long arm of a right triangle.