26 Math Review Part 2 Inches to Feet & Areas

Division 80 ÷ 5 = 16 Also written as: 5 80 1 6 5 3 30

Multiplication and Division 6 x 5 x 4 = 120 4 x 6 x 5 = 120 10 ÷ 5 x 4 = ? 10 ÷ (5 x 4) = 1/2 (10 ÷ 5) x 4 = 8 (10 x 4) ÷ 5 = 8

Multiplication and Division 0.56 x 0.35 = ? 0.56 x 0.35 = .196 0.56 ÷ 0.35= ? 0.56 ÷ 0.35 = 1.6 0.56 x 0.007 = .00392 0.56 ÷ 0.007 = 80 0.007 ÷ 0.56 = 0.0125

Multiplication and Division What is 6 feet 3 inches in feet? 1 foot = 12 inches 3 inches = 3 ÷ 12 = 0.25 feet 6 + 0.25 = 6.25 feet

Area Calculations For Squares and rectangles the area (A) is equal to length (L) x width (W) or A = L x W Width Length

Area Calculations A = L x W Square L = W = 3 3 x 3 = 9 Square Something Width = 3 Length = 3

Area Calculations For Squares and rectangles the area (A) is equal to length (L) x width (W) or A = L x W Width = 6 feet 3 inches Length = 3 feet

Area Calculations For Squares and rectangles the area (A) is equal to length (L) x width (W) or A = L x W Width = 6 feet 3 inches = 6 + (3 ÷ 12) = 6.25 feet Length = 3 feet A = L x W = 3 x 6.25 = 18.75 square feet

Area of a Triangle For any triangle with a right angle the area is the length multiplied by the width (of the two legs meeting at the right angle) divided by 2.

Area of a Right Triangle For any triangle with a right angle the area is the length multiplied by the width (of the two legs meeting at the right angle) divided by 2.

Area of a Right Triangle For any triangle with a right angle the area is the length multiplied by the height of the two legs where the right triangle is divided by 2. 90o 90o 90o 90o 90o = right angle

Area of a Triangle For any triangle with a right angle the area is the length multiplied by the height of the two legs where the right triangle is divided by 2. 90o 90o Length 90o 90o Width

Area of a Triangle A = hb X b ÷ 2

Area of a Triangle A = hb X b ÷ 2 hb 90o 90o

Area of a Triangle A = hb X b ÷ 2 hb 90o 90o b

Area of a Triangle A = hb X b ÷ 2 = hb= 6’ 90o 90o b = 14’ A = 6 X 16 ÷ 2 = 48 Sq. Ft.

Area of a Triangle Calculate the wall area for the following drawing: 3.66 ft 8.0 ft 18.75 ft

Area of a Triangle Calculate the wall area for the following drawing: 3.66 ft 8.0 ft X 18.75 ft = 150 ft2 8.0 ft 18.75 ft

Area of a Triangle Calculate the wall area for the following drawing: 3.66 ft hb b 18.75 ft 8.0 ft 3.66 ft X 18.75 ft ÷ 2 = 34.3 ft2

Area of a Triangle Calculate the wall area for the following drawing: 3.66 ft 34.3 ft2 8.0 ft 150 ft2 18.75 ft

Area of a Triangle Calculate the wall area for the following drawing: 3.66 ft 34.3 ft2 8.0 ft 150 ft2 150 ft2 + 34.3 ft2 = 184.3 ft2 18.75 ft

Area of a Circle A = 3.14 x R x R Radius = R Diameter = 2 x R

Area of a Circle A = 3.14 x R x R Radius = ½ R = 4 inches Diameter = 8 inches A = 3.14 x 4 x 4 A = 50.24 square inches

Area of a Circle A = 3.14 x R x R Radius = ½ R = 4 inches Diameter = 8 inches A = 3.14 x 4 x 4 A = 50.24 square inches

Area of a Circle A in square inches = A in square feet 12 x 12 = 144 50.24 ÷ 144 = ? A = 50.24 square inches 0.3488888888888…

Measuring Areas in Cubic Feet

Step 1 Finding the Area/Volume in Cubic Feet Calculate the wall area for the following drawing: 3.66 ft 34.3 ft2 8.0 ft 150 ft2 150 ft2 + 34.3 ft2 = 184.3 ft2 18.75 ft

Step 2 Find the Length 184.3 ft2

Step 2 Find the Length 184.3 ft2 40.3 ft

Step 3 Multiply Area X Length 184.3 ft2 X 40.3 ft = 7,427.29 ft3 40.3 ft

Converting Units Converting 6 inches of Mercury into Inches of Water Inches of Mercury are multiplied by 13.6 to get inches of water 6” of Mercury = 13.6 x 6 = 81.6 inches of water Note: 81.6” ÷ 12” = feet of water = 6.8’

Converting Units Convert 82 Inches of Water to Inches of Mercury Inches of water are multiplied by 0.0735 to get Inches of Mercury 82” x 0.0735 = 6.027” of Mercury

Converting Units LPS x 0.472 = CFM CFM x 2.12 = LPS HP x 0.746 = Kilowatts 1Watt = 3.412 Btu/h Ft of H2O x 0.433 = psi psi x 2.31 = Ft of H2O [F0 – 32] x 5/9 = C0 [C0 x 9/5] + 32 = F0 h = Ppsia ÷ 0.433 Ppsia = psi + 14.7 Tons of Refrigeration = HP x 4.716 Tons of Refrigeration = BTU/minute x 200 Note: HP x 4.716 = Btu/minute x 200

Converting Units Square inches are divided by 144 to get square feet 72 in2 = ? Ft2 72 ÷ 144 = 0.5 Ft2 Note: Ft2 x 144 = in2

Using Equations 3 600 3 x 200 = = 2 400 2 x 200 2 400 = 3 600

Using Equations Fan Law CFMnew RPMnew = CFMold RPMold CFMold RPMold = CFMnew RPMnew

Using Equations = x = x x = 3 600 2 400 3 600 400 400 2 400 3 400 600

Using Equations Fan Law CFMnew RPMnew = CFMold RPMold CFMnew x = RPMold RPMnew CFMold