# Area of a Triangle: Area = X B X H

Crusenberry 7.16.13

Measurement

Scale / A number line on a measurement toolCustomary system / Most standard rules, yardsticks and tape measures

Elapsed time / The amount of time that passes from the start of an event or activity to the end of that event or activity

Perimeter / A measure of the distance around the outside edge of a figure

Circumference / The perimeter of a circle

Area / The measure of the surface within a given regions

Square units / Area is measured in this

Surface area / The area of each face of a geometric solid, and then add those areas together to find the total

Volume / The space occupied by – or the space inside – a solid, measure in cubes called cubic units

Formulas:

Perimeter = (2xL) + (2xw)

Circumference = π x d

Area = l x w

Area of a triangle: Area = ½ x b x h

Area of a circle: Area = πr2

Volume = s3

**Reading a scale – **

10 X 20 X 30

What number is the red x pointing to? 14

What number is the blue x pointing to? 28

Each tick mark represents? 2

**Using a customary ruler – **

**Practice practice – measure different things in your room. **Remember that each mark is a 16th of an inch. So you land on the ninth mark that is past the number 4, that length is 4 and 9/16

**Measuring to a fraction of an inch – **

**Practice practice – measure different things. **Remember that each mark is a 16th of an inch.

Measure a penny, nickel, dime , and a quarter

**Reviewing customary units of measure – **

Estimate the temperature in a refrigerator; the width of a dime, the weight of a dinner roll, and the

capacity of a soup can.

Which is greater?

15 inches or 1 foot

5 feet or 2 yards

22 ounces or 1 pound

3 cups or 1 quart

90 minutes or two hours

Answers: 15 inches, 2 yards, 22 ounces, 1 quart, two hours

**Converting units within the customary system – ** pg 134

**Reviewing metric units of measure – **pg 135

**Converting units within the metric system – **pg 136

**Comparing customary and metric units – **pg 137

**Adding and subtracting mixed measurements – **

1 hour 15 minutes

+ 2 hours 50 minutes

3 hours 65 minutes

- 60 minutes **add that hour to the 3 you already have

4 hours 5 minutes

3 feet 3 inches

- 1 foot 9 inches **you cannot take 9 from 3, so you must borrow

2 feet 15 inches **add the 12 inches( 1 foot) you borrowed and add it to the 3 inches you already have

- 1 foot 9 inches

1 foot 6 inches

**Calculating time – ** pg 139

**Finding elapsed time –**

9 hours 15 minutes

- 2 hours 30 minutes **you cannot take 30 from 15, so you must borrow

8 hours 75 minutes **add the 60 minutes (1 hour) you borrowed and add it to the 15 min you already have

- 2 hours 30 minutes

6 hours 45 minutes

**Finding perimeter – ** pg 141

**Finding circumference – **pg 142

**Finding area of squares and rectangles – **pg 143

**Finding the area of a triangle – ** pg 144

**Finding the area of a circle – **pg 146

**Finding surface area –** pg 147

Finding volume – pg 148