Answer:
∠1=∠9=43°, ∠2=∠7= 17°, ∠4=∠5=∠6=60°, ∠3=∠8=120°
Step-by-step explanation:
Given ABC is an isosceles triangle and DBE is an equilateral triangle. we have to find each missing measure.
In triangle ABC,
∠1=∠9 (∵isosceles triangle)
⇒ 4x+3=9x-47
⇒ 9x-4x=3+47 ⇒ 5x=50 ⇒ x=10
Hence, ∠9=∠1=(4x+3)°=4(10)+3=43°
Also, given ΔBDE is an equilateral triangle, and all angle of equilateral triangle are equal.
∴ ∠4+∠5+∠6=180°
⇒ ∠4+∠4+∠4=180° ⇒ 3∠4 = 180° ⇒ ∠4 = 60°
∴ ∠4=∠5=∠6=60°
By exterior angle property, ∠3=∠5+∠6=60°+60°=120°
∠8=∠5+∠4=60°+60°=120°
In ΔABD, ∠1+∠2+∠3=180°
⇒ 43°+120°+∠2=180°⇒ ∠2 = 17°
In ΔABD, ∠9+∠8+∠7=180°
⇒ 43°+120°+∠7=180°⇒ ∠7= 17°
