If ABCDE is a regular pentagon, find the value of (y + z - x).

If ABCDE is a regular pentagon, find the value of (y + z - x). Correct Answer 36°

Calculation:

/n

⇒ Angle of a pentagon = /5 = 108°

In a triangle ABE,

⇒ ∠ABE = ∠AEB (∵ AE = AB)

⇒ ∠BAE = 108°

⇒ ∠BAE + ∠ABE + ∠AEB = 180°

⇒ 108° + 2∠AEB = 180°

⇒ ∠AEB = 36° = y

⇒ Δ ABE ≅ Δ BCD

⇒ ∠CBD = 36°

⇒ ∠BDC = z = 36°

⇒ ∠ABC = ∠ABE + ∠DBE + ∠CBD

⇒ 108° = 36° + x + 36°

⇒ x = 36°

⇒ y + z - x = 36° + 36° - 36° = 36°

∴ Required answer is 36°.

Related Questions

In a regular pentagon ABCDE, ratio of area of ΔACD and area of ΔAED.