Answer:
The number of terms in the sequence is 9
Step-by-step explanation:
We want to get the number of terms
Mathematically, we have the formula for the sum of terms in an arithmetic sequence as

a represents the first terms, and i represent the last term

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Answer:
24 cm
Step-by-step explanation:
30^2 = 18^ 2 + a ^2 according to the Pythagorean theorem