This quant practice question is a geometry problem solving question. Concept tested: Number of triangles in a polygon.
Find the number of triangles in an octagon.
- Cannot be determined
Correct Answer Choice (3). An octagon has 56 triangles
No three vertices of a polygon will line on a straight line. Therefore, joining any 3 vertices of a polygon will result in a triangle.
An n-sided polygon will have n vertices.
Number of triangles that can be formed = number of ways of selecting 3 vertices out of n vertices = nC3.
An octagon has 8 sides and 8 vertices.
In this question n = 8 => number of triangles =8C3 = 56.
The correct answer is Choice (3).
XAT TANCET Practice Questions - Listed Topic wise
- Number Theory
- Permutation Combination
- Coordinate Geometry
- Data Sufficiency
- Profit Loss
- Ratio Proportion
- Mixtures & Alligation
- Speed Distance & Time
- Pipes, Cisterns & Work, Time
- Simple & Compound Interest
- Averages & Statistics
- Progressions : AP, GP & HP
- Set Theory
- Clocks Calendars
- Linear & Quadratic Equations
- English Grammar
- General Awareness