Answer:
A triangle with side lengths 4 cm, 5 cm, and 15 cm
Step-by-step explanation:
In order to form a triangle with given side lengths, sum of any two sides must always be greater than the third side.

The answer is 64. cubic miles because its 4 x 4 x 4 = 64
Step-by-step explanation:
sin²α − sin⁴α
Factor out sin²α.
sin²α (1 − sin²α)
Use Pythagorean theorem.
(1 − cos²α) cos²α
Distribute.
cos²α − cos⁴α
The answer is in the pic.