Answer:
21 +7√3
Step-by-step explanation:
The lengths of the sides of a 30°-60°-90° triangle have the ratios ...
1 : √3 : 2
so the perimeter in "ratio units" is
1 + √3 + 2 = 3+√3.
Your triangle has dimensions a factor of 7 larger, so its perimeter is ...
7·(3 +√3) = 21 +7√3 . . . . triangle perimeter
