How to find a missing side length of a non right triangle?

Aline on the wall and a line on the floor are skew. always, sometimes, or never?

Aplot of land has been surveyed for a new housing development with borders ab, bc, dc, and da. the plot of land is a right trapezoid with a height of 60 feet and an opposite leg length of 65 feet

Find the area of an equilateral triangle with a side of 6 inches