The base of a trinagle is increased by 20% and it’s height is increased by 30%. by what percent is the area of the triangle increased?

Lets say the base is x and the height is y. The new base would be 1.2x and the new height would be 1.3y

Area of a triangle is base times height divided by 2:

1.2x*1.3y/2 = (1.2*1.3 + x*y)/2 = 1.56xy/2 = 0.78xy = 78% of xy

But a normal area would be 50% of xy

78% - 50% = 38%

ANSWER: 38% increase

, 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