# Objective - To use formulas to solve problems. Objective - To use formulas to solve problems. Formula - An algebraic equation that describes a relationship between two or more variables. Rate Time = Distance r t d 60 miles 5 hr d 1 hr 300 mi d Find the area of the circle below using the formula A r 2 (Use 3.14). r = 4 in. A r 2 A 3.14 (4) 2 A 3.14 16 A 50.24 in 2 Use the formula F = ma to find the force, F, exerted

by a mass, m, of 12 kg accelerating at 5 m/s 2. F m a F 12 kg 5m/s m 12 kg 2 F 12 5 kg m/s 2 F 60 kg m/s 2 a 5m/s 2 5 Use the formula, C (F 32) , to change the 9 temperature of 59 Fahrenheit to Celsius. 5 C (F 32) 9 5 C (59 32) 9

5 C (27) 9 9 3 C 5 27 15 9 1 1 1 C 15 59 F 15 C Mark borrows \$500 from the bank at 6% simple annual interest for 4 years. Use the formula, I = Prt, to find what interest he owes. P 500 r 6% 0.06 t 4 Interest I P r t I (500)(0.06)(4)

I 120 Interest owed \$120 Perimeter and Area Formulas Figure Perimeter Area Square s P = 4s A s 2 s Rectangle w l Parallelogram P = 2l + 2w

A l w Perimeter and Area Formulas Figure Perimeter Area Square s P = 4s A s 2 s Rectangle w P = 2l + 2w A l w P = 2a + 2b

A b h l a Parallelogram h b Triangle a h b Perimeter and Area Formulas Figure Perimeter Area Square s P = 4s

A s 2 s Rectangle w P = 2l + 2w A l w P = 2a + 2b A b h l a Parallelogram h b Triangle a h

b Perimeter and Area Formulas Figure Perimeter Area Square s P = 4s A s 2 s Rectangle w P = 2l + 2w A l w P = 2a + 2b

A b h P=a+b+c A 1 b h 2 l a Parallelogram h b Triangle a h b c Use formulas to find the perimeter and area of the figure below. 1) 6 in. 5 in.

7 in. Perimeter P = 2a + 2b P = 2(6) + 2(7) P = 12 + 14 P = 26 inches Area A b h A 7 5 2 A 35 in Use formulas to find the perimeter and area of the figure below. 2) 5 cm 6 cm 3 cm 9 cm Perimeter

P=a+b+c P=5+6+9 P = 20 cm Area 1 A bh 2 1 A 9 3 2 1 A 27 2 2 A 13.5 cm Find the area of the trapezoid given the formula 1 A b1 b 2 h . 2 1) 8m

5m 6m 7m 1 A b1 b 2 h 2 1 A 8 6 5 2 1 A 14 5 2 A 7 5 35 m 2