To find the number of sides ($n$) of a polygon, we use the formulas for its interior and exterior angles.
We are given that the difference between the interior and exterior angles is $36^\circ$.
Given: $I - E = 36^\circ$
$ \frac{(n-2) \times 180^\circ}{n} - \frac{360^\circ}{n} = 36^\circ $
$ \frac{(n-2) \times 180^\circ - 360^\circ}{n} = 36^\circ $
$ \frac{180^\circ n - 360^\circ - 360^\circ}{n} = 36^\circ $
$ \frac{180^\circ n - 720^\circ}{n} = 36^\circ $
$ 180^\circ n - 720^\circ = 36^\circ n $
$ 180^\circ n - 36^\circ n = 720^\circ $
$ 144^\circ n = 720^\circ $
$ n = \frac{720^\circ}{144^\circ} $
$ n = 5 $
Therefore, the polygon has 5 sides.
ABCDEF is a regular hexagon. Side of the hexagon is 36 cm. What is the area of the triangle AOB ?
If ∆ABC ~ ∆DEF, and BC = 4 cm, EF = 5 cm and the area of triangle ABC = 80 cm 2, then the area of the triangle DEF is:
If Δ ABC is right angled at B, AB = 12 cm and ∠CAB = 60°, determine the length of BC.
If ΔABC and ΔDEF are congruent triangles, then which of the following is FALSE?
D and E are points on the sides AB and AC, respectively, of ΔABC such that DE is parallel to BC and AD ∶ DB = 7 ∶ 9. If CD and BE intersect each other at F. then find the ratio of areas of ΔDEF and ΔCBF.