You seem to have gotten m∠2. Remember that ∠1 and ∠2 are alternate interior angles, meaning they're both equal. Since they gave you m∠1 as being 26°, you now know the measure of ∠2.
As for m∠3 and m∠4, If you look at ∠3 you'll see that it is complementary to ∠1 (They both add up to 90°), so if you subtract m∠1 from 90° you'll have found m∠3. You find m∠4 the same way.
