What is the best next step in the construciton of the perpendicular bisetor of ab?

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angle measure.

Select the lengths in centimeters that would form a right triangle

Solve: 25 points find the fifth term of an increasing geometric progression if the first term is equal to 7−3 √5 and each term (starting with the second) is equal to the difference of the term following it and the term preceding it.