A lawn 60 $m$ by 40 $m$ has two cross paths, each 3 $m$ wide, running through its middle parallel to the sides (yellow). Paving costs ₹20 per $m^2$. Find the cost of paving the paths.

**Area of a parallelogram = base × height.**

Same idea as a rectangle, but the height is the perpendicular distance between the two parallel sides — NOT the slant length of the side. Pick any side as the base, drop a perpendicular to the opposite parallel side, measure that — that's the height.

Example: parallelogram with base 8 cm and perpendicular height 5 cm. Area = $8\times 5=40{\text{cm}}^2$. The slant side could be longer; doesn't matter for area.

Perimeter of a parallelogram = 2 × (one side + adjacent side).