Mathematics Grade 10 15 min

Area and perimeter in the coordinate plane: Set 2

Area and perimeter in the coordinate plane: Set 2

Tutorial Preview

1

Introduction & Learning Objectives

Learning Objectives Calculate the perimeter of complex polygons using the Distance Formula. Determine the area of any simple polygon using the Shoelace Formula. Find the area of composite figures by decomposing them into simpler shapes like triangles and rectangles. Apply the 'boxing-in' method to find the area of non-standard polygons. Verify properties of geometric figures using coordinate geometry formulas before calculating area and perimeter. Solve multi-step problems involving area and perimeter on the coordinate plane. Ever wondered how a GPS calculates the area of a park or a property lot just from its corner coordinates? 🗺️ Let's learn the powerful geometry behind it! This tutorial moves beyond simple squares and focuses on complex and composite shap...
2

Key Concepts & Vocabulary

TermDefinitionExample Coordinate PolygonA polygon whose vertices are defined by ordered pairs (x, y) in the Cartesian coordinate plane.A triangle with vertices at A(1, 2), B(5, 6), and C(3, -1). Distance FormulaA formula derived from the Pythagorean theorem used to find the straight-line distance between two points in the coordinate plane.The distance between (2, 3) and (5, 7) is sqrt((5-2)^2 + (7-3)^2) = sqrt(3^2 + 4^2) = sqrt(25) = 5 units. Shoelace FormulaA method to calculate the area of any simple polygon given the coordinates of its vertices in order.For a triangle with vertices (x1, y1), (x2, y2), (x3, y3), the area is 0.5 * |(x1y2 + x2y3 + x3y1) - (y1x2 + y2x3 + y3x1)|. Decomposition MethodThe process of finding the area of a complex polygon by breaking it down into simpler, non-o...
3

Core Formulas

The Distance Formula d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2} Use this formula to find the length of any segment in the coordinate plane, which is essential for calculating the perimeter of a polygon. (x₁, y₁) and (x₂, y₂) are the coordinates of the two endpoints. The Shoelace Formula Area = \frac{1}{2} |(x_1y_2 + x_2y_3 + ... + x_ny_1) - (y_1x_2 + y_2x_3 + ... + y_nx_1)| A powerful formula for finding the area of any simple polygon. List the n vertices (x₁, y₁), ..., (xₙ, yₙ) in counter-clockwise order and repeat the first vertex at the end. Sum the products of the downward diagonals and subtract the sum of the products of the upward diagonals. Area of a Triangle (Coordinate Method) Area = \frac{1}{2} |x_1(y_2 - y_3) + x_2(y_3 - y_1) + x_3(y_1 - y_2)| This is a simp...

4 more steps in this tutorial

Sign up free to access the complete tutorial with worked examples and practice.

Sign Up Free to Continue

Sample Practice Questions

Challenging
Three vertices of a parallelogram ABCD are A(1, 1), B(5, 2), and C(6, 5). Which of the following are possible coordinates for the fourth vertex, D?
A.(3, 3)
B.(2, 4)
C.(0, 5)
D.(4, -2)
Challenging
A triangle with vertices A(1, 4), B(5, 2), and C(k, 6) has an area of 10 square units. Which of the following is a possible value for k?
A.3
B.5
C.-10
D.7
Challenging
A rectangular park is defined by vertices R(0,0), S(10,0), T(10,8), and U(0,8). A triangular garden with vertices P(2,2), Q(8,2), and M(5,6) is built inside the park. What is the area of the park that is NOT covered by the garden?
A.80 square units
B.12 square units
C.68 square units
D.92 square units

Want to practice and check your answers?

Sign up to access all questions with instant feedback, explanations, and progress tracking.

Start Practicing Free

More from Area and Perimeter (Review)

Ready to find your learning gaps?

Take a free diagnostic test and get a personalized learning plan in minutes.