C language only

1. Write a C program to input sides of a triangle and check whether triangle is valid or not (Hint: if sum of any two sides of a triangle is greater than the third side then the triangle is valid) 2. Write a C program to input all angles of a triangle and check whether triangle is valid or not. (Hint: sum of all angles of any triangle is 180 degrees) 3. Read a character from user and check if it is a valid hexadecimal digit or not. Hint: a char is a valid hexadecimal digit if it is one of these characters: ' 0 ', ' 1 ', ... , '9', ' a ', ' b ', ... , 'f', 'A', 'B', ... 'F' 4. Read a floating point number from user and check if it has any fractional part (e.g. 4.5, 6.9,...) or not (e.g. 4,5,. . If it has a fractional part then print "Not an integer", otherwise print "integer". 5. Write a C program that reads the radius r of a circle and the side a of a square from user and then checks if that square can be placed inside that circle or not. Hint: Use Pythagorean theorem