How do you find the area of a triagnle and a rhombus in gerneral

The area of a triangle is calculated using 1/2b*h, where b = the base and h = the height

The area of a rhombus is calculated using pq/2, where p and q equal the length of the diagonals from opposite points.

it will cost dollar $540

the living room is 3 which means if we divide 325/3 then we get $108

therefore if 1part of the living room cost $108 and 3 costed $325

then total 5part of the room will cost 5*108 which gives $540