15b is the answer to this question hope this was helpful
Answer: Area of ΔABC is 2.25x the area of ΔDEF.
Step-by-step explanation: Because equilateral triangle has 3 equal sides, area is calculated as

with a as side of the triangle.
Triangle ABC is 20% bigger than the original, which means its side (a₁) measures, compared to the original:
a₁ = 1.2a
Then, its area is


Triangle DEF is 20% smaller than the original, which means its side is:
a₂ = 0.8a
So, area is


Now, comparing areas:

2.25
<u>The area of ΔABC is </u><u>2.25x</u><u> greater than the area of ΔDEF.</u>
Let's make an equation.
19,000x=24,320
This equation shows the percentage increase, which is x. Once we have x, we need to subtract 1 from it since in the equation the 1 shows that it's increeasing. All we need to do is divide both sides by 19,000.
24,320÷19,000
1,28-1=0.28; we need to multiply by 100 to find the increase.
0.28×100=28
So, the percentage increase is 28%.
Circumference, C = 2
r. Find the radius using this formula then use it to find the area with A = 
.
OR use the formula A = 
Hope it helps. mark as brainliest if it does...
Answer:
Step-by-step explanation:
The area of a trapezoid is the average of the parallel bases times the height.
A=h(a+b)/2 and since we have two identical trapezoids the total are will be
A=h(a+b) in this case
A=15(32+25)=855mm^2