Respuesta :
Answer:
Area of remaining plastic = 36.55 cm² (Approx.)
Step-by-step explanation:
Given:
Diameter of plastic dial of telephone = 8 cm
Diameter of middle hole = 4 cm
Diameter of ten small holes = 1.2 cm
Find:
Area of remaining plastic
Computation;
Radius of plastic dial of telephone = 8/2 = 4 cm
Radius of middle hole = 4/2 = 2 cm
Radius of ten small holes = 1.2/2 = 0.6 cm
Area of remaining plastic = Area of plastic dial - Area of middle hole - 10[Area of small holes]
Area of remaining plastic = π(4)² - π(2)² - π(0.6)²
Area of remaining plastic = π(16) - π(4) - π(0.36)
Area of remaining plastic = π[16 - 4 - 0.36]
Area of remaining plastic = π[11.64]
Area of remaining plastic = (3.14)(11.64)
Area of remaining plastic = 36.5496
Area of remaining plastic = 36.55 cm² (Approx.)
