angles architecture black-and-white building buildings cambodia concrete construction construction-work dangers daylight distance distant frame framework galvanised galvanized gray grey greyscale metal metalic monochrome multi-storey multi-story people ribbed ribbing risks risky roof roof-trusses roofing safety sheeting sheets shelter sheltered steel structural-work structure trusses upper-storey upper-story workmen angle-iron angled background bolted bolts braced bracing building-construction building-site building-work color coloration colors colour colours connected connecting constructing frames house joined light metalwork New open preliminary-framework reinforced reinforcements reinforcing secure shadows solid space spacious strength strong sunlight unfinished