Idiot\'s Guides Basic Math and Pre-Algebra

Chapter 14: Quadrilaterals 189 To find the area of parallelogram ABCD, it’s not enough to know that AB = 13 meters and BC = 10 m ...

190 Part 3: The Shape of the World MATH TRAP To get units squared, you need to multiply units by units, that is, feet times feet ...

Chapter 14: Quadrilaterals 191 The height of the parallelogram is half the height of the trapezoid. The base of the parallelogra ...

192 Part 3: The Shape of the World Polygons with More than Four Sides Although triangles and quadrilaterals are the polygons you ...

Chapter 14: Quadrilaterals 193 Not right. If your vertices were A, B, C, D, and E, the diagonal from C to A is the same diagonal ...

194 Part 3: The Shape of the World CHECK POINT Find the number of diagonals in an octagon (8 sides). Find the total of the meas ...

Chapter 14: Quadrilaterals 195 A regular polygon has a center point, and the radius, or distance from the center to a vertex, is ...

196 Part 3: The Shape of the World The Least You Need to Know Parallelograms have both pairs of opposite sides parallel. Area f ...

CHAPTER 15 Circles .......................................................................................... In This Chapter E ...

198 Part 3: The Shape of the World The Language of Circles Take a piece of string and tie a pencil to one end. Pin the other end ...

Chapter 15: Circles 199 Arcs are named by the points at each end of the arc, with an arc symbol over the top, but that isn’t alw ...

200 Part 3: The Shape of the World MATH IN THE PAST Not every curve is a circle or part of a circle. Ancient mathematicians look ...

Chapter 15: Circles 201 draw two chords in the same circle and the two chords are the same length, then the arcs they cut off wi ...

202 Part 3: The Shape of the World Suppose that in circle O, OA and OB are radii and AC and BC are chords. If AB 50 , find m’AO ...

Chapter 15: Circles 203 But then you notice that ’2 is also an exterior angle of that triangle and equal to exactly the same thi ...

204 Part 3: The Shape of the World Lines and Angles ............................................................................ ...

Chapter 15: Circles 205 The figure shows two secants that cross at P. One cuts the circle at B and then again at A. The other cr ...

206 Part 3: The Shape of the World When an angle is formed by two tangents, the circle is broken into two arcs. When two secants ...

Chapter 15: Circles 207 A T B D C If the chord you drew happened to be a diameter, both intercepted arcs would be 180r, so both ...

208 Part 3: The Shape of the World Area and Circumference When you explored polygons, whether triangles, quadrilaterals, or poly ...