Chapter 11 Basic Geometry

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Math1060HomeworkChapter112Solutions.docx

Chapter 11 Basic Geometry Homework Name___________________________________

You may use a calculator.

Sketch and label.

1)

Acute

Solution:

Acute angles in an angle less than 900

A

B

CA

Find the square root.

2)

324

Solution:

because

Answer:

For #3 and #4, find the measure of the requested angle.

3) Find the complement of 41°.

Solution:

Let A be the complement of 41°. Sum of complement angles is 90°. So A+41°=90°

A+90°-41°=49°

Answer: The complement of 41° is 49°

4) What is the measure of the angle that is supplementary to 119°?

Solution:

Let B be the supplementary 119°. Sum of supplementary angles is 180°. So B+119°=61°

A+90°-41°=49°

Answer: The supplementary of 119° is 61°

In a right triangle, find the length of the side not given. Let c represent the length of the hypotenuse. Use correct units in your answer.

5) a = 7 in., b = 24 in.

Solution:

Use pythagoras theorem, a and b are the two short sides and c is the hypotenuse, so.

, and.

Answer: The length of the hypotenuse is 25 in.

For #6 - #9, find the perimeter and area. Use correct units in your answers.

6) A square with side 1.5 in.

Solution:

Let one side of the square be, and since all 4 sides are equal then the perimeter is and the area is

Perimeter:,

Area:,

Answer: The Perimeter of the Square is 6 in and the area is 2.25 in2.

7) An equilateral triangle with side 25 ft

Solution:

Let one side of the equilateral triangle be, and since all 3 sides are equal then the perimeter is and the area is

Perimeter:,

Area: ,

Answer: The Perimeter of the equilateral triangle is 75 ft and the area is ft2.

8)

10 m

24 m

Solution:

Let the length of the rectangle be and the width of the rectangle be. The perimeter of the rectangle is and the area is

Perimeter: ,

Area: ,

Answer: The Perimeter of the rectangle is 68 m and the area is 240 m2.

9) The sides are each 3.6 feet in length.

4 ft

3 ft

8 ft

Solution:

Let the length of the 2 parallel lines and and the perpendicular height. The perimeter of the trapezoid rectangle is and the area is

Use Pythagoras theorem to find

Perimeter: ,

Area: ,

Answer: The Perimeter of the trapezoid is 22 ft and the area is 18 ft2.

10) Find the area and circumference. Use correct units in your answers. Use Use u = 3.14 to approximate pi.

14 mi

Solution:

The radius of the circle is. The Area of the circle and Circumference is .

Area: ,

Perimeter: ,

Answer: The Area of the circle is 153.86 mi2 and the circumference of the circle is 43.96 mi2.

11) Find the perimeter. Use correct units in your answer.

7

9 in.

4 in.

5 in.

7 in.

8 in.

Solution:

The perimeter is the sum of all sides:

Perimeter:

Answer: The perimeter is 33 in.

For #12 - #13, find the volume. Use u = 3.14 when needed. Use correct units in your answers.

12)

7.5 cm

6.8 cm

4.5 cm

Solution:

The Volume of the Cuboid:

Volume, where is the length, is the width and is the height.

,

Answer: The volume of the cuboid is 229.5 cm3.

13)

r = 36

ft

Solution:

The Volume of the Sphere:

Volume , where is the radius of the sphere.

Answer: The volume of the Sphere is 195333.12 ft3.

For #14 and #15, find the unknown values for side lengths or angle measurements. Use correct units in your answers.

14)

35°

94°

Solution:

The Sum of a triangle add upto 180°:

X+94°+35°=180°

X=180°-94°-35°=51°

Answer: The angle of X is the triangle 51°.

15)

6 cm c

8 cm

Solution:

By Pythagoras Theorem:

Answer: The length of side c of the triangle is 10 cm.

The two triangles below are similar. Find x and y.

16)

5.4

3.6

Solution:

Using ratios,

To find x , then

To find y , then

Answer: The length x is 4.2 and y is 3.6.

17) The picture shows the intersection of several streets in a city. Is the angle formed by E Post Street and Sampson Street below Post Street acute or obtuse?

Solution:

Acute angles in an angle less than 900 and obtuse angle is an angle greater than 900 but less than 1800. So the angle formed by E Post Street and Canyon Road S is 900, and since the angle formed by E Post Street and angle Sampson Street below Post Street is less than 900.

Answer: The angle formed by E Post Street and Sampson Street below Post Street is acute angle.

For #18 - #20, solve. Use u = 3.14 when necessary.

18) A water sprinkler sends water out in a circular pattern. The radius of watering is 6 feet. Determine how large an area is watered. Write your answer in complete sentence form and include correct units.

Solution:

The radius of the circle is. The Area of the circle .

Area: ,

Answer: The Area of the circular pattern is 113.04 feet2.

19) An airplane flying due south is 300 miles from the airport. Another airplane flying due west is 325 miles from the airport. How far apart are the two airplanes? Round to the nearest mile. Write your answer in complete sentence form and include correct units.

Solution:

Airplane flying due south is 300 miles from the airport and airplane flying due west is 325 miles.

It makes an angle of 900 at the airport.

Applying pythogaras theorem, to get distance d between the airplanes, use .

Distance:

Answer: The two airplanes are 442 miles apart.

20) A one- story building is 400 ft by 320 ft. If a square patio with sides 29 ft occupies the center of the building, how much area remains for offices? Write your answer in complete sentence form and include correct units.

Solution:

The area of the building is , .

The area of the Square pation, , .

The remaining area of the building is .

Answer: The area remains for the office is 127159 ft2.

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