Step-by-step explanation:
sides of equilateral triangle are all equal
so to find length of one side divide perimeter by 3
80/3 is the length of each side
60° will be angle of each side bcz equilateral
area of triangle is 1/2 *b*h
to find height=
sin60= opp/(80/3)
opp=23.09
so height is 23.1
now u can calculate area
1/2*b*h
1/2*80/3*23.1
308units²
