Developing proof fill in the blanks to complete this proof of theorem 2-4.
all right angles are congruent.
given: x and y are right angles.
prove: 2x = 2y
proof: x and a. ? are right angles because it is given.
by the definition of b. ? ,m x = 90 and m2y = 90.
by the transitive property of equality, m 2x = c. ? .
because angles of equal measure are congruent, d. ? .

Part A 
7.8 is rational  because it can be written as a fraction 78/100 or 39/50

Part B

7.7^2 = 59.29 and 7.8^2 = 60.84
so an irrational number betwee 7.7 and 7.8 would be  sqrt 60.  Radicals like these ( like sqrt2 , sqrt10 that are not perfect squares)  have irrational square roots).

sqrt 60  = 7.75 to the nearest hundredth

if you try 'square root of 60'on a scientific calculator it usually gives you up to 9 decimal places  Mine gives 7.745966692  but the decimals go on without bounds,