52) What is the drawing instrument used for measuring angle?

53) What is the drawing instrument used for measuring angle?

54) What is the third angle of a triangle if the sum of its two angle is 112 Degree?

55) What is a plane figure bound by a curve formed by the locus of a point that moves so that it is always at a fixed distance from a stationary point is its centre?

56) What is the liner length of the entire curve that is equal to Pi x D? (D is the diameter)