円、三角形、正方形、長方形、平行四辺形、台形の面積

Area of Circle, Triangle, Square, Rectangle, Parallelogram, Trapezium, Ellipse and Sector Area of Plane Shapes Area is the size of a surface! Learn more about Area , or try the Area Calculator . Triangle Area = ½ × b × h b = base h = vertical height Square Area = a 2 a = length of side Rectangle Area = w × h w = width h = height Parallelogram Area = b × h b = base h = vertical height Trapezoid (US) Trapezium (UK) Area = ½(a+b) × h h = vertical height Circle Area = π × r 2 r = radius Ellipse Area = π ab Sector Area = ½ × r 2 × θ r = radius θ = angle in radians Note: h is at right angles to b Example: What is the area of this rectangle? The formula is: Area = w × h w = width h = height We know w = 5 and h = 3 , so: Area = 5 × 3 = 15 Example: What is the area of this circle? Radius = r = 3 Area = π × r 2 = π × 3 2 = π × (3 × 3) = 3.14159... × 9 = 28.27 (to 2 decimal places) Example: What is the area of this triangle? Height = h = 12 Base = b = 20 Area = ½ × b × h = ½ × 20 × 12 = 120 A harder example: Example: Sam cuts grass at $0.10 per square meter How much does Sam earn cutting this area: Let's break the area into two parts: Part A is a square: Area of A = a 2 = 20m × 20m = 400m 2 Part B is a triangle. Viewed sideways it has a base of 20m and a height of 14m. Area of B = ½b × h = ½ × 20m × 14m = 140m 2 So the total area is: Area = Area of A + Area of B = 400m 2 + 140m 2 = 540m 2 Sam earns $0.10 per square meter Sam earns = $0.10 × 540m 2 = $54 1754, 1755, 1756, 1757, 1758, 1759, 1760, 1761, 3250, 3251 Area Calculation Tool Area Area of Irregular Polygons Geometry Index Copyright © 2024 Rod Pierce