How many diagonals can be drawn by joining the vertices of an octagon?
20
Concept used :
Number of diagonals in polygon = [n(n - 3)]/2 (where n is the number of sides)
Calculations :
Here n will be 8 as octagon has 8 sides.
Number of polygons in octagon = [8 × (8 - 3)]/2
⇒ (8 × 5)/2
⇒ 40/2 = 20
∴ Option 1 will be the right choice.
Important Questions from Quadrilaterals
What is the value of AC 2– BD 2
What is the point of intersection of the diagonals?
What is the area of the parallelogram?
ABCD is a cyclic quadrilateral. Diagonals BD and AC intersect each other at E. If ∠BEC = 138° and ∠ECD = 35°, then what is the measure of ∠BAC?
A circle is inscribed in a quadrilateral ABCD, touching sides AB, BC CD and DA at P, Q, R and S, respectively. If AS = 6 cm, BC = 12 cm, and CR = 5 cm, then the length of AB (in cm) is:
