How would you apply the cosine angle difference identity to find the exact value of cos 75o? cos (100.5o – 25.5o) cos (120o – 45o) cos (180o – 75o) cos (30o + 45o)

The construction of copying qpr is started below. the next step is to set the width of the compass to the length of ab. how does this step ensure that a new angle will be congruent to the original angle? by using compass take the measures of angle and draw the same arc according to it.