Answer with explanation:
In a triangle sum of two sides , should always be greater than the third side.
Sides of the given triangle are, 3 x cm, 7 x cm and h cm.
1.
3 x + 7 x > h
→ 10 x > h
2.
3 x+ h > 7 x
→h > 7 x -3 x
→h> 4 x
3.
7 x + h > 3 x, which will be always true.
Combining 1, 2 and 3 we get
→4 x < h < 10 x
Option A