1) with this question. will mark brainliest + 10 points.

To form a triangle we need any two sides add up to be greater then the third one.
a+b>c ; 240+121=361>263 ✅
a+c>b ; 240+263=503>121✅
b+c>a ; 121+263=384>240✅
Yes we can form a triangle with those dimensions.
Area of triangle^2=S( S-a)(s-b)(s-c)
Where S= (a+b+c)/2=(240+121+263)/2=312
Area of triangle^2=
312(312-240)(312-121)(312-263)=210240576
Area of triangle = Square root (210240576)
=14499.67503
~14,499.68

Im pretty sure it’s is b 1.6 mi