ConstructionModerate1 mark
3(iii)
Use ruler and compass for the following construction:
construct an equilateral triangle ABC of side 5 cm.
Topic: Geometrical construction
Previous-year question practice database
Answer
Solution diagram
Exam answer
Steps of construction:
- Draw AB = 5 cm.
- With centre A and radius 5 cm, draw an arc.
- With centre B and radius 5 cm, draw another arc meeting the first at C.
- Join AC and BC.
Since AB = BC = CA = 5 cm, ΔABC is equilateral.
Explanation
An equilateral triangle has all three sides equal. The two arcs ensure C is 5 cm from both A and B.
More from Constructions (Circles)
construct the circumcircle of ΔABC.2026give the geometrical name of quadrilateral ABCD2026Statement 1: The point which is equidistant from three non-collinear points D, E and F is the circumcenter of the ΔDEF.
Statement 2: The incenter of a triangle is the point where the bisector of the angles intersects.2025Use ruler and compass for the following construction. Construct a ΔABC, where AB = 6 cm, AC = 4.5 cm and ∠BAC = 120°. Construct a circle circumscribing the ΔABC. Measure and write down the length of the radius of the circle.2025Using 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.2023Using ruler and compass construct a triangle ABC where AB = 3 cm, BC = 4 cm and ∠ABC = 90°. Hence construct a circle circumscribing triangle ABC. Measure and write down the radius of the circle.2020