 Hello and welcome to the session. In this session, we are going to discuss the following question. And the question says that, write negation of the following statements and find their truth value. P in a triangle, an exterior angle is equal to the sum of opposite interior angles. The second sentence is q, 2 is an irrational number and the third r, 1 plus 3 is equal to 4. We know that negation of a statement p is not p and is symbolized as this. Also, a statement and its negation have opposite truth value and opposite meaning. With this key idea, we shall proceed with the solution. Now, according to the question, we have to find the negation of the given statements. The first statement is p in a triangle and exterior angle is equal to the sum of two opposite interior angles. To write negation, we shall make use of the word not and the negation of p is written as in a triangle, an exterior angle is not equal to the sum of two opposite interior angles. Now, this is a false statement. So, the truth value of negation of p is false. The second statement is q, 2 is an irrational number. Negation of q will be, 2 is not an irrational number. Now, we know that 2 is not an irrational number. So, the statement not q that is 2 is not an irrational number is a true statement. So, the truth value of negation of q is t. The third statement is r that is 1 plus 3 is equal to 4. Negation of r that is not r is 1 plus 3 is not equal to 4. As we know, 1 plus 3 is equal to 4. So, the statement not r is a false statement. So, the truth value of negation of r is f. This is the required answer. With this, we complete our session. Hope you enjoyed the session.