Answer:
sometimes, if their average angle is over 45 degrees
never are 2 obtuse angles summing to 180 degrees
always. two 90 degree angles always sum to 180 which is a straight line
Answer: 
Step-by-step explanation:
Given: Number of cards in a standard deck = 52
If we already chosen a diamond card, then the number of cards left in the deck =52-1=51
The number of spades remains same = 13
Now, the probability that you choose a spade, given that you have already chosen a diamond is given by :-

Hence, the the probability that you choose a spade, given that you have already chosen a diamond 