Practice Quiz You may use a calculator. Homework: Study 20 minutes tonight Have parent sign on the top of your practice quiz! 1. Triangle ABC is similar to triangle DEF. What is the value of x? Small Triangle Big Triangle Triangle’s Side Triangle’s Base 3 8 • Set up proportions and label • Use cross products to solve • • • • • 3 (2x) = 40 6x = 40 X = 4.66666… Round to 4.7 Insert value of x for 2x 2 (4.7) = 9.4 5 2x 2. A photograph 8 inches wide by 10 inches long is scaled to 4.5 inches long in a magazine. What is the width of the published picture? Photo #1 Photo #2 8 10 4.5 x Wide Long • Set up proportions and label • Use cross products to solve • 8 x = 4.5 (10) • 8x = 45 • X = 5.625 3. Jana is 1.5 meters tall and casts a 6-meter shadow. How long is the shadow of a 12-meter flagpole beside her? Object Jana Flagpole 1.5 meters X meters • Set up proportions and label • Use cross products to solve • 1.5 (12) = 6x • 18 = 6x • X = 3 meters Shadow 6 meters 12 meters 4. The end of a 500-foot kite string is anchored to the ground. At a point 10 feet along the string from the anchor point, the string is 5 feet above the ground. How high is the kite flying? String Height above Ground Kite Anchor Point 500 Feet 10 Feet x 5 Feet • (I imagine the kite is flying at a diagonal because of the wind. ) • Set up proportions and label • Use cross products to solve • 500 (5) = 10 x • 2500 = 10x • X = 250 feet 5. Two cities are separated by 3.7 inches on a map. The actual distance between the cities is 11.1 miles. What is the map scale? Map Inches Miles 3.7 inches 11.1 miles Scale 1 x • We are looking to find out how many miles 1 inch equals. • 11.1 (1) = 3.7 x • 1 inch = 3 miles (must include the full rate for map scales- not just one number) 5. Two cities are separated by 3.7 inches on a map. The actual distance between the cities is 11.1 miles. What is the map scale? Map Inches Miles 3.7 inches 11.1 miles Scale 1 x • We are looking to find out how many miles 1 inch equals. • 11.1 (1) = 3.7 x • 1 inch = 3 miles (must include the full rate for map scales- not just one number) 5. Two cities are separated by 3.7 inches on a map. The actual distance between the cities is 11.1 miles. What is the map scale? Map Inches Miles 3.7 inches 11.1 miles Scale 1 x • We are looking to find out how many miles 1 inch equals. • 11.1 (1) = 3.7 x • 1 inch = 3 miles (must include the full rate for map scales- not just one number) 5. Two cities are separated by 3.7 inches on a map. The actual distance between the cities is 11.1 miles. What is the map scale? Map Inches Miles 3.7 inches 11.1 miles Scale 1 x • We are looking to find out how many miles 1 inch equals. • 11.1 (1) = 3.7 x • 1 inch = 3 miles (must include the full rate for map scales- not just one number) 5. Two cities are separated by 3.7 inches on a map. The actual distance between the cities is 11.1 miles. What is the map scale? Map Inches Miles 3.7 inches 11.1 miles Scale 1 x • We are looking to find out how many miles 1 inch equals. • 11.1 (1) = 3.7 x • 1 inch = 3 miles (must include the full rate for map scales- not just one number) 6 A model boat is 15 inches long. If it is built to a scale of 1: 250, how long is the boat in real life? Model Scale Boat • • • • • 1 15 inches 15 (250) = 1 x 11.1 (1) = 3.7 x X = 3750 inches Divide by 12 to put in feet 312.5 feet Actual 250 x 5. Two cities are separated by 3.7 inches on a map. The actual distance between the cities is 11.1 miles. What is the map scale? Map Inches Miles 3.7 inches 11.1 miles Scale 1 x • We are looking to find out how many miles 1 inch equals. • 11.1 (1) = 3.7 x • 1 inch = 3 miles (must include the full rate for map scales- not just one number) 7 The length of a racing car is 14 feet. A scale model of the racing car is 8 inches long. What scale was used to build the model? Race Car Inches Miles 14 feet x Scale 8 inches 1 inch • Looking to find out how much 1 inch equals • 14 (1) = 8 • 1. 75 feet = 1 inch (must include the full rate for map scales- not just one number) 8 A packing machine can pack 2500 boxes in 4 hours. At what rate does the machine work? Packing Machine Boxes Hours 2500 boxes 4 hours Rate x 1 • We are looking to find how many boxes per hour, so it is out of 1 hour • 2500 (1) = 4 x • 625 boxes per hour 9 A cow produces 230 gallons of milk in 6 days. At that rate, about how many gallons should the cow produce in one year? Rate Milk Days 230 gallons 6 days x 1 = 365 days • Convert 1 year to days so you are comparing the same thing • 230 x 365 = 6x • 83,950 = 6x • 13,991.666… round to 13,991.7 gallons 10. If the tree is 60 feet tall, how tall is the building? Bush Height Shadow 4.5 9 Tree 60 x Building x 72 • Don’t use info about tree- not complete. Use bush instead! • You can use proportion or notice the shadow is 2x longer 36 feet 11. Central angle for 30% soccer? Degrees Part (Soccer) Whole 30% 100% • 30 (360) = 100 x • 11,800 = 100 x • 625 degrees Percent x 360* 12. Central angle for 20% track? Degrees Part (Track) Whole 20% 100% • 20 (360) = 100 x • 7200 = 100 x • 72 degrees Percent x 360* 13. Central angle for 27% swimming? • . Part (Swimming) Whole Degrees Percent 27% x 100% 360* • 27 (360) = 100 x • 9729= 100 x • 97.29 degrees 14) Answer: 43.2 degrees 15. 15. Describe the cross section formed by the intersection of a rectangular pyramid and a shape the is parallel to its base. • Cross section is a rectangle 16. A circle has a radius of 13.5 mm. What is the circumference? Use 3.14 for pi and round to the nearest tenth. • • • • • Circumference = 3.14 (diameter) C = 3.14 ( 13.5 + 13.5) C = 83.21 Round 83.2 mm 17. Challenge: (Harder than problems on actual test!) The area of a circle is 64 p in2. What is the diameter of the circle? • Area = 3.14 (radius x radius) • 64 = 3.14 ( r r) • Divide by 3.14 on both sides – 64/ 3.14 = rr – 26.38 = rr • Square route both sides – 5.135 • Round – 5.1 inches 18. A circular pond has a radius of 11 m. What is the area? Use 3.14 and round to the nearest tenth. • • • • • • Area = 3.14 (radius x radius) A = 3.14 ( 11 x 11) C = 3.14 x 121 C = 379.94 Round 379.9 meters squared 19. The area of a circle is 314 square inches. Find the diameter of the circle. • Area = 3.14 (radius x radius) • 314 = 3.14 ( radius x radius) • Divide both sides by 3.14 – 100 = radius x radius • Radius = 10 • Diameter = 20 inches 20. Describe the cross section formed by the intersection of a rectangular prism and a plane perpendicular to its base. • Perpendicular means 90 degress • The cross section will be a rectangle