Answer:
A ≈ 9.0 ft²
Step-by-step explanation:
70° = 7π/18 radians
Area of the arc section
A = ½(7π/18)8² = 12⁴/₉π ft² = 39.09537 ft²
As the triangle is isosceles, the other two angles are (180 - 70) / 2 = 55°
law of sines 8 / sin55 = L / sin 70 L = 9.17722
so the triangle height = √(8² - (9.17722/2)²) = 6.55321
Area of triangle ½(6.55321)(9.17722) = 30.07016
Area = 39.09537 - 30.07016 = 9.025211 ≈ 9.0 ft²