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

Crusenberry 7.16.13

Measurement

Scale / A number line on a measurement tool
Customary 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

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