A cone has a circular base, a perpendicular height of 21cm and a semi vertical angle 30degree. calculate the slant height of the cone. Find the area of its (take pie to 22/7​

The lengths of two sides of a triangle are 9 and 15. what can be said about the length of the third side? a. it must be greater than or equal to 6 and less than 24. b. it must be greater than or equal to 6 and at most 24. c. it must be greater than 6 and less than 24. d. it must be greater than 6 and at most 24.