The sides of a triangular lot measure 36 yd, 92 yd and 115 yd . Find the area of the lot using Heron's formula

Question

I feel like this is another really east one and I feel even more dummy. Please and thank you for explaining with work and an answer.

Answer 1

s = ½(a + b + c), where a,b,c are the 3 sides, and "s" is the triangle's semi-perimeter.

s = ½(36+92+115) = 243/2 = 121.5

Area = √{ ( 121.5 - 36) + ( 121.5 - 92) + ( 121.5 - 115) } = 11.0 Yd²