Tom can paint one side of a triangular wall of base 16

Solution

Area of one side of the triangular wall = (1/2) × base × height = (1/2) × 16 × 21 = 168 m²
So, painting efficiency of Tom = 168 ÷ 14 = 12 m²/day
Area of one side of the circular wall = π × r² = (22/7) × (42/2) × (42/2) = (22/7) × 21 × 21 = 1386 m²
So, total area painted by Ram and Tom = 1386 + 324 = 1710 m²
Out of which, area painted by Tom = 30 × 12 = 360 m²
So, area painted by Ram = 1710 - 360 = 1350 m²
So, painting efficiency of Ram = 1350 ÷ 30 = 45 m²/day
So, area painted by Ram in 21.6 days = 45 × 21.6 = 972 m² = 75% of the area of one side of the rectangular wall
So, 100% of area of one side of the rectangular wall = 972 ÷ 0.75 = 1296 m²
And so, length of the rectangular wall = 1296 ÷ 24 = 54 meters