For 23, you only know 1 set of numbers, which is the hypotenuse. The numbers are 5 and 10. The difference is that the second triangle is 2 times more than the 1st. So the answer is 3 times 2 and 4 times 2 which is 6 and 8, or A. For 24, notice the second figure is 360 less than the first. The 3rd is 180 less than the 2nd. So it only makes sense that the 4th would be 90 less than the 3rd. So D is the most probable answer.