Unit 5 Test Review

(1 point) If the area of a circle is 169 π 𝑖𝑛^2, find the radius of the circle.

• A) 13 𝑖𝑛

• B) 16 𝑖𝑛

• C) 26 𝑖𝑛

• D) 169 𝑖𝑛

Answer explanation

Main Ideas/Understandings:

* Quantities can be expressed in terms of π

* Finding AREA involves multiplication(circle: A = πr^2)

* Divide out π on both sides* *Use square root as an inverse operation

(1 point) A triangle with side lengths a, b, and c is shown below. Which statement about the side lengths must be true?

• A) b + c < a

• B) a + b > c

• C) a + c < b

• D) a + b < c

Answer explanation

Main Ideas/Understandings:

* Use the Triangle Inequality Theorem

* The sum of any 2 sides is greater than the third

* less than (pointy <)

* greater than ( > open)

(1 point) The octagon shown below has eight congruent sides. The given measures of the octagon are rounded to the nearest tenth of a centimeter. What is the area, to the nearest square centimeter, of the octagon?

• A) 324

• B) 86

• C) 48

• D) 12

Answer explanation

Main Ideas/Understandings:

* Finding AREA involves multiplication (modifier, base, height)

* You can decompose a figure into shapes whose area formulas you know

* AREA is additive

(1 point) A cylinder and a cone have congruent heights and radii. What is the ratio of volume of the cone to the volume of the cylinder?

• A) 9 : 1

• B) 6 : 1

• C) 5 : 1

• D) 3 : 1

Answer explanation

Main Ideas/Understandings:

* 1 cylinder has the same volume as 3 cones.

* You compare 2 quantities through a ratio

(1 point) To fix a light that is 8 meters off the ground, Mr. Lisa leans a ladder against the side of the school. The base of the ladder is 6 meters from the building. How long is the ladder that Mr. Lisa is using?

• A) 48 meters

• B) 14 meters

• C) 10 meters

• D) 2 meters

Answer explanation

Main Ideas/Understandings:

* know that ladder is the hypotenuse

* know how to use the formula to find hypotenuse

* know how to solve for a missing side

(1 point) Which set of lengths are not the side lengths of a right triangle?

• A) 12, 16, 22

• B) 8, 15, 17

• C) 9, 12, 15

• D) 3, 4, 5

Answer explanation

Main Ideas/Understandings:

* Know the "Purple Sheep" strategy

* Use A and B for the smaller numbers

* Select the answer that ≠

(1 point) Which number line shows the values √5, 2.1, √9, 5/3, and 𝝅 plotted correctly on a number line, in order from least to greatest?

• A)

• B)

• C)

• D)

Answer explanation

Main Ideas/Understandings:

* Know how to turn any number into decimal form

* Know that smallest #'s come first

* Line up #'s using original form

(1 point) A tree struck by lightning broke at a point 10 feet above the ground as shown. What was the length, in feet, of the broken part of the tree? Round to the nearest foot.

• A) 18

• B) 17

• C) 16

• D) 15

Answer explanation

Main Ideas/Understandings:

* broken tree part -> hypotenuse

* missing hypotenuse -> add numbers squared

* round to nearest foot -> target is the ONES place

(1 point) A 15-foot ladder is set up 4 feet from the base of a building. How far up the building does the ladder reach? Round your answer to the nearest tenth of a foot.

• A) 15.6

• B) 15.5

• C) 14.5

• D) 14.4

Answer explanation

Main Ideas/Understandings:

* Know that the ladder is C

* Missing leg -> subtract squares

* Round to nearest tenth -> target is the 1st decimal

(1 point) Camp Sunshine is on a lake in upstate New York. The map shows the distances in meters. Use the Pythagorean Theorem to find the distance between Francesca’s house and Camp Sunshine. Round to the nearest tenth of a meter.

• 26.9

• 68.0

• 71.6

• 95.0

Answer explanation

Main Ideas/Understandings:

* Diagonal distance can't be counted

* When counting is inconvenient, subtract corresponding coordinates

* Round to nearest tenth -> target is 1st decimal