Mathematics
The angles of a pentagon are in the ratio 2 : 5 : 6 : 4 : 3. The largest angle is:
54°
135°
162°
108°
Rectilinear Figures
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Answer
According to the properties of polygons, if a polygon has n sides, then the sum of its interior angles is (2n - 4) x 90°.
A pentagon have 5 sides.
Sum of its interior angles = (2 x 5 - 4) x 90°
= (10 - 4) x 90°
= 6 x 90°
= 540°.
It is given that the interior angles of the pentagon are in the ratio 2 : 5 : 6 : 4 : 3.
So,
⇒ 2a + 5a + 6a + 4a + 3a = 540°
⇒ 20a = 540°
⇒ a =
⇒ a = 27°
The angles are:
⇒ 2a = 2 x 27° = 54°
⇒ 5a = 5 x 27° = 135°
⇒ 6a = 6 x 27° = 162°
⇒ 4a = 4 x 27° = 108°
⇒ 3a = 3 x 27° = 81°
Thus, the largest angle = 162°.
Hence, option 3 is the correct option.
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