No, battleships did not try to angle their armour. The effect was known - for example, the images at the bottom of this website show British calculations of the ranges at which the belts and decks of various ships could be penetrated, including the effect of angle. However, it came second to other tactical concerns. Typically, a battlefleet would engage in line astern, each ship following behind the one in front. Admirals would try to navigate their line such that their line was crossing the bows or stern of the opposing fleet ('crossing the T'), or, failing that, was on a parallel course to the enemy. This had two advantages. Firstly, it simplified communications and control, a factor particularly necessary in WWI when radio technology was primitive. When each ship just had to follow the one in front, there was little chance for chaos and disruption; the fleet could easily operate as a unified tactical force. Secondly, it allowed the fleet to bring as many guns to bear as possible; crossing the T of the opposing fleet brought the advantage that the enemy could not do so. Accuracy of naval gunfire was low. During WWI, 5% accuracy was a good performance; during WWII, things were not much better. To ensure that enough hits were scored to sink an enemy ship, a high volume of fire was needed. To obtain this, the ship needed to be broadside on, so that every turret could be brought to bear. The RN of WWII was about the only fleet that did not fight in line of battle. Instead, it split up the battleline into several semi-autonomous divisions. This was done to allow the RN to close more effectively, and to reduce the effectiveness of manoeuvres by the opposing fleet - if it turned to cross the T of one division, it's T would be crossed by another. Ships did manoeuvre to reduce the accuracy of enemy fire, zig-zagging to throw off attempts at rangefinding. They did not manoeuvre to increase the effectiveness of their armour.