Perp. height (right)
4 units
Slanted side (trap)
4.0 units
True area
24 sq units
Right: Area = base × perpendicular height = 6 × 4 = 24
Trap: base × slanted side = 6 × 4.0 = 24.0 ← too big!
Drag the brass dot to lean the shape. Watch: the slanted side (red) keeps getting longer, but the true perpendicular height (mustard dashed) stays the same — and so does the area. Using the slant is the classic mistake.