25(a)Circle TheoremsMedium1 markThe diagram shows a circle, centre O and diameter AC. B is a point on the circumference of the circle.Give the geometrical reason why angle ABC=90∘.AThe angle between a tangent and a radius is 90∘BAngles in a triangle add up to 180∘CThe angle at the centre is twice the angle at the circumferenceDThe angle in a semicircle is 90∘EAngles in the same segment are equalFOpposite angles of a cyclic quadrilateral add up to 180∘GThe perpendicular from the centre to a chord bisects the chordHThe base angles of an isosceles triangle are equalIThe angle between a tangent and a chord equals the angle in the alternate segmentGrade answerSolutionGrading criteria
25(b)Pythagoras Theorem Right Angled TrigonometryEasy2 marksCalculate AC.AC=cmGrade answerSolutionGrading criteria
25(c)Pythagoras Theorem Right Angled TrigonometryEasy2 marksCalculate angle BAC.angle BAC=∘Grade answerSolutionGrading criteria