Practicing Success
ABCDE is a regular pentagon. Its sides are extended as shown in the figure. The value of \(\frac{∠ABC\;+\;5∠EGD\;+\;2.5∠BAJ}{9}\)is? |
108° 36° 72° 52° |
52° |
In Pentagon ABCDE Interior angle = \(\frac{180\;×\;(n\;-\;2)}{n}\) \(\frac{180\;×\;(5\;-\;2)}{5}\) = 108° ⇒ Interior angle = ∠ABC = ∠BAE = 108° ⇒ ∠BAJ = 180° - ∠BAE = 180° - 108° = 72° ⇒ ∠GED = ∠GDE = 72° ⇒ ∠EGD = 180° - (72° + 72°) = 36° Now, ATQ, ⇒ \(\frac{∠ABC\;+\;5∠EGD\;+\;2.5∠BAJ}{9}\) = \(\frac{108°\;+\;(5\;×\;36°)\;+\;(2.5\;×\;72)}{9}\) = 52° |