If the two edges of the arc is connected like a D, yes, it has 2 right angles
an ovalish shape, like this () Or perhaps a semicircle.
All triangles inscribed in a semicircle with one side of the triangle being the diameter of the semicircle are right triangles.
The cross section of the Ram hemi is a semicircle
a sphere
The diameter of the semicircle will be twice the radius.
an ovalish shape, like this () Or perhaps a semicircle.
None because it has 1 straight side and no angles
If, by square corners, you mean corners that are right angles, then any polygon with four or more sides can have two square corners. Furthermore, apart from near the corners, the lines need even be straight so the shape need not be a polygon. In the limit a semicircle has two right angles.
No, a semicircle is not a quadrilateral
Semicircle
The possessive form is semicircle's.
Calculating the radius of a semicircle depends on what information about the semicircle is given.
A semicircle means a half circle.
A semicircle has 180 degrees
Semicircle has four syllables.
A right angle triangle will fit into a semicircle.
All triangles inscribed in a semicircle with one side of the triangle being the diameter of the semicircle are right triangles.