The union army's victory in the capture of was probably critical to lincoln's reelection in 1864.

The Union army's victory in the capture of  Atlanta was probably critical to Lincoln's reelection in 1864.

Explanation:

The surrender of Atlanta to Union Gen. William T.  Sherman on September 2,  1864, helped increased the chances of president Abraham Lincoln to get reelected. Before that event, many politicians and observers were pessimistic about his chances, because it had been a rather bad year for the Union army.  

angle a = 40.6°

step-by-step explanation:

for any right angle triangle we know the pythagoras theorem reveals

hypotenuse² = height²+base²

by this formula we will calculate the length of hypotenuse

h² = 6²+7²

⇒ h =√36+49 = √85 = 9.22

now from the given triangle sin a = height/ hypotenuse

                                                sin a = 6/9.22 = 0.651

therefore

so angle a = 40.6°