Final answer:
The area of Triangle B is 4 times the area of Triangle A.
Step-by-step explanation:
To find the area of Triangle B, we need to compare the ratio of the sides between Triangle A and Triangle B. Since Triangle B has sides that are twice as long as Triangle A, the ratio of the sides is 2:1.
The area of a triangle is proportional to the square of its sides, so if the side length is doubled, the area is multiplied by 2^2 = 4.
Therefore, the area of Triangle B is 4 times the area of Triangle A, which is 50cm^2. So, the area of Triangle B is 4 * 50cm^2 = 200cm^2.