1. Area Day 2 Math 10-3 Ch. 3 Measurement

2. Ex1. Determine the area of the following shape. *First, find the formula for the area of a TRIANGLE: Area triangle = b x h Fill in the formula with the information from the diagram. A Tri = x 8 ft x 3 ft Now solve. *remember, multiplying by is the same as dividing by 2! 8 x 3 2 = 12 ft 2

3. Ex2. Determine the area of the following shape. *First, find the formula for the area of a PARALLELOGRAM: Area Parallelogram = b x h Fill in the formula with information from the diagram: A p = b x h = 12 cm x 7 cm = 84 cm 2

4. Ex3. Determine the area of the following shape. First, find the formula for the area of a TRAPEZOID: Area Trapezoid = (b1+b2) x h Fill in the formula with information from the diagram: A Trap = (9 mm + 4 mm) x 3 mm *First, you must add (9 + 4) because they are in BRACKETS. Remember BEDMAS? 9 + 4 = 13 13 x 3 2 = 19.5 mm 2

5. Ex4. The area of a triangle is 12 in 2. If the base of the triangle is 6 in long, what is the height of the triangle? A Triangle = 12 in 2 b = 6 in h = ? We are looking for the height! Fill in the formula for area of a triangle with what we already know: A Triangle = b x h 12 in 2 = 6 in x h 2 What is the opposite of dividing by 2? Multiply by 2 on the other side! 12 x 2 = 6 x h 24 = 6 x h

6. Ex4. The area of a triangle is 12 in 2. If the base of the triangle is 6 in long, what is the height of the triangle? 24 = 6 x h What is opposite of multiplying by 6? Divide by 6 on the other side! 24 6 = h h = 4 in Double check to make sure: A Triangle = b x h = 6 x 4 2 = 12 in 2

7. Ex5. The area of a square is 16 cm 2. What is the length of one side? Fill in the formula for area of a square with what we already know: A Square = s 2 16 cm 2 = s 2 But we don’t want s 2 we want just s ! What is the opposite of squaring something? Square rooting!

8. Find the button on your calculator. This is the operation you use to “un-square” a number. 16 = s 2 = s s = 4 cm Double check to make sure: A square = s 2 = s x s = 4 x 4 = 16 cm 2

9. How do we convert between SI square units? Remember, the SI measuring system is based on 10.

10. Ex6. 8 m 2 is how many cm 2 ? HAVE m 2 WANT cm 2 Start at m 2 and follow the arrows to cm2  we have to multiply by 10 2 twice! *Remember 10 2 is the same as 10 x 10 ! 8m 2 x 10 2 x 10 2 = 8 m 2 x 10 x 10 x 10 x 10 = 80000 cm 2

11. Ex7. 350 mm 2 is how many dm 2 ? HAVE mm 2 WANT dm 2 Start at mm 2 and follow the arrows to dm 2  we have to divide by 10 2 twice! 350mm 2 10 2 10 2 = 350 10 10 10 10 = 0.035 dm 2

12. How do we convert between Imperial square units? Remember, the Imperial Measurement System is based on referents!

13. Ex8. 9 yd 2 is how many in 2 ? HAVE ft 2 WANT in 2 Start at yd 2 and follow the arrows to in 2  We have to x 3 2 and then 12 2 ! 9 yd 2 x 3 2 x 12 2 = 9 yd 2 x 3 x 3 x 12 x 12 = 11664 in 2

14. Ex9. 2 016 in 2 is how many ft 2 ? HAVE in 2 WANT ft 2 Start at in 2 and follow the arrows to ft 2  We have to divide by 12 2 ! 2016 in 2 12 2 = 2 016 12 12 = 14 ft 2