Given the following attributes how many triangles can be formed angle 100° angle 90° side length 5 cm

Answer is    b. 80, 99, 120to get from 15 to 24, you add 9 (from 24 - 15).to get from 24 to 35, you add 11 (from 35 - 24).to get from 35 to 48, you add 13 (from 48 - 35).to get from 48 to 63, you add 15 (from 63-48).you are incrementing by rate of change that is increased by two after each increase.so for the text term of the sequence you need to add 17 to 63.    63 + 17 = 80increase rate of change, 17, by two to get 19 as rate of change.now add 19 to 80.    80 + 19 = 99increase rate of change, 19,  by two to get 21 as rate of change.now add 21 to 99.    99 + 21 = 120the next three terms are 80, 99, 120