Answer:
(i) Triangle ABC and triangle ADE are similar triangles. Hence, their ratios will be same.
Ratio of DE to BC is 4:6 => 2:3
To find area, we need to raise the ratio of length to power 2
(2/3)² = 16/x
4/9 = 16/x
x = (16*9)/4
x = 36cm²
Therefore, area of triangle ABC is 36cm²
(ii) Ratio of DE to BC is 4:8 => 1:2
(1/2)² = 25/x
1/4 = 25/x
x = 25*4
x = 100cm²
Therefore, area of triangle ABC is 100cm²
I'm not sure about the third question, sorry
Explanation: