The length of the hypotenuse of a 30°-60°-90° triangle is 7. Find the perimeter.

7/2+21/2sqrt3
21+7sqrt3
7+21sqrt3
21/2+7/25sqrt3

Ths sides of a 30-60-90 triangle are in the ratios 1:√3:2

so, you have scaled things by 7/2, making the sides
7/2:7√3/2:7

7/2 + 7√3/2 + 7 = 7/2 (3 + √3)
= 21/2 + 7/2 √3

Is that 7/25√3 a typo?