ConstructionHard4 marks
Using ruler and compass construct a triangle ABC in which AB = 6 cm. ∠BAC = 120° and AC = 5 cm. Construct a circle passing through A, B and C. Measure and write down the radius of the circle.
Topic: Geometrical construction
Previous-year question practice database
Answer
Solution diagram
Exam answer
Construction completed; measure the radius of the circumcircle from the supplied construction image.
Explanation
Steps: draw AB=6 cm; at A construct 120°; mark AC=5 cm; join BC; construct perpendicular bisectors of two sides; their intersection O is circumcentre; with centre O and radius OA draw the circumcircle. Measure OA.
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