Answer:

Explanation:
recall that sine is the ratio of the opposite side (to the angle) and the hypotenuse (longest side).
since this is a right triangle, we can use Pythagoras theorem to find the hypotenuse here. recall
where a, b and c are side lengths and c is the hypotenuse.
thus, we have

then taking the square root of both sides, we have
.
so, we have to take the ratio of the opposite side to
, and the hypotenuse.
the opposite side is 70.
so,
. dividing both sides by 2, we have
. thus, we have reached our solution.