19) Which drawing instrument is used to draw circles and arcs?

20) What is the distance from the centre to any point on the circle?

21) What is the part of a circle with horizontal and vertical radii making 90 Degree to each other?

22) What is the term for a quadrilateral whose all four sides are equal and its four angles are right angles?

23) What is the term for a quadrilateral if opposite sides are equal and parallel and all four sides are right angles?