What is the measure of
ABC

A. 88 degrees

Step-by-step explanation:

Subtract the two given angle measures 131 and 53 from 360

131 + 53 = 184

360 - 184 = 176

Divide 176 by 2 since angle ABC and DBE have the same angle measure.

176 / 2 = 88

, and

for

step-by-step explanation:

we can analyze the pattern at which the terms increase. let us denote , , , so that we can call

note the following:

the pattern: to get the next term value, we just add the next term number (e.g. 1st, 2nd, to the previous term value (term values are the given numbers in the question, 1, 3, 6, 10, 15,

from , to get to , we add

from , to get to , we add

etc.

we need to form a recursive formula, a formula that has the next term as a function of the previous term. so a possible recursive formula can be

, and for