1. Geometry: Measuring Two-Dimensional Figures
Chapter 11
Geometry: Measuring Two-Dimensional Figures

2. Lesson 11-1 Squares and Square Roots
Square – The product of a number and itself.
Perfect Square – Numbers like 9, 25, and 16 that are the squares of rational numbers.
Square Roots – The factors multiplied to form perfect squares.
Radical Sign – (√) the symbol used to indicate the positive square root of a number.

3. Lesson 11-2 Estimating Square Roots
To estimate the square root of a number that is not a perfect square, list the perfect squares it is between. Find the square root of each number. Your estimate will be the one it is closer to.
Rational Number – Any number that can be written as a fraction (integers, repeating decimals, terminating decimals).
Irrational Number – A number that cannot be written as a fraction.
THE SQUARE ROOT OF ANY NUMBER THAT IS NOT A PERFECT SQUARE IS AN IRRATIONAL NUMBER.

4. Lesson 11-3 Pythagorean Theorem
Pythagorean Theorem – Describes the relationship between the length of the hypotenuse and the lengths of the legs of a triangle:
a2 + b2 = c2
Legs - The two side adjacent to the right angle.
Hypotenuse – The side opposite the right angle.

5. Lesson 11-4 Area of Parallelograms
Area of a Parallelogram – A = bh
(area equals base times height).
Base – any side of a parallelogram.
Height – the length of the segment perpendicular to the base with endpoints on opposite sides.

6. Lesson 11-5 Area of Triangles and Trapezpoids
Area of a Triangle: A = ½ bh
(area equals ½ * base * height)
Area of a Trapezoid: A =1/2h(b1+b 2)
(area equals ½ * the height * the sum of the bases).