1. COURSE 3 LESSON 4-6
Formulas
Find the area of a trapezoid with height of 6 cm and bases of 5.2 cm and 7.5 cm.
A = h (b1 + b2)
Use the formula for the area of a trapezoid. 1 2
= (6.0) ( ) Substitute. 1 2
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2. Formulas (continued) = (6.0)(12.7) Add within the parentheses.
COURSE 3 LESSON 4-6
Formulas
(continued) 1 2
= (6.0)(12.7) Add within the parentheses.
= 3(12.7) Multiply from left to right.
= 38.1 Simplify.
The area of the trapezoid is 38.1 cm2.
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3. COURSE 3 LESSON 4-6
Formulas
Find the time it takes a sled-dog team to go 95 miles if their average rate is 19 mph.
The problem gives distance and rate. Use the distance formula, d = rt where d is the distance traveled, r is the rate of travel, and t is the time spent traveling.
d = rt Use the distance formula.
95 = 19 • t Substitute 95 for d and 19 for r.
Divide each side by 19 to isolate t on the right. 95 19
19 • t =
5 = t
Simplify. 95 19 t =
It took the sled-dog team 5 hours to go 95 miles.
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