Option C. 12√3
Step-by-step explanation:
Lateral area of the solid figure will be = 3×(one lateral side )
Area of a lateral side of the given triangle = (1/2) × (height) × (Base)
Height of an isosceles triangle with a side 4 will be = √(4² - 2²) = √(16-4)= √12 = 2√3
Now area of one lateral side = (1/2)×(2√3)×(4) = 4√3
Therefore lateral area of the solid figure = 3×(4√3) = 12√3