CAN SOMEONE HELP ME PLEASE!!! I WILL GIVE THE BRAINIEST AND 100 POINTS!!!

Step-by-step explanation:
the length of hypotenuse =
√(21²+28²) = √(441+784)
= √1225
= 35 yd
the perimeter of triangle =
21+28+35 = 84 yd
the area of triangle =
½×21×28 = 294 yd²
Answer: 35 yd
Step-by-step explanation:
28^2+21^2=1225
√1225
=35