Select the Venn diagram that best represents the relationship between the following classes.
Triangles, Figures with a right angle, Equilateral triangles
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) →
In a Venn diagram two circles overlap when some members belong to both classes, one circle lies inside another when every member of the first belongs to the second, and circles stay apart when the classes have no common member.
Every equilateral triangle is a triangle, so its circle lies inside the triangle circle
A right-angled triangle is a triangle with a right angle, while a square or a rectangle has right angles but is not a triangle, so the circle of figures with a right angle overlaps the triangle circle and goes outside it
Each angle of an equilateral triangle is \(60^\circ\), so it never has a right angle: the right-angle circle stays apart from the equilateral circle
A small circle inside a large one, and a third circle crossing only the large one, as in Option (2)
