0.333... as a fraction it’s repeating fraction and 0.666 as a repeating fraction

Express the following as a function of a single angle, cos(60) cos(-20) - sin(60) sin(-20)

Can someone me and plz do the problem

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