no
No because it could be a right angled trapezoid. A rectangle must have four right angles. Yes, a parallelogram with a right angle is always a rectangle. In fact, in my geometry book, some 55 years ago such was the definition of rectangle. A parallelogram with one right angle will always have four right angles. The right angled trapezoids that are not rectangles are not parallelograms.
For all triangles, right-angled included, it is the multiplication of the base length times the perpendicular height x half. Algebraically A = 0.5bh For a right-angled triangle it is the base length times to length of right angled (perpendicular) line times one half.
The circumradius of a right angled triangle would be equal to half the length of its hypotenuse.
acute angled triangle,right angled triangle,obtuse angled triangle,isosceles triangle,equilateral triangle, scalene triangle
yes it can
It can, but need not.
trapezoid
Yes, it is.
In a right angled triangle the two other angles are acute.
There is no specific name, but "right-angled polygon" will suffice.
trapezoid
equalataril, right-angled, scaline and issossalies