Page 816 - Algebra 1

3. Write an equation for a direct variation that includes the point, (24, 3). (56)
*4. If ∠A = 77°, find sin A, cos A, and tan A to the nearest ten-thousandth. (117)
*5. Error Analysis Two students are finding the measure of ∠A. Which student is (117) correct? Explain the error.
Student A Student B
A
13
B
9
C
__ tanA= 9 tanA=13
13 9
_9 -1 -1
tan-1(tan A) = tan-1( ) tan
13 9
)
A ≈ 34.7° A ≈ 55.3°
*6. Geometry In a right isosceles triangle, the acute angles are congruent. Find the (117) measures of the acute angles. Then use the sine or cosine ratio to find the length of a leg of a right isosceles triangle to the nearest hundredth if the hypotenuse is
5 centimeters.
*7. Multi-Step You are standing on the roof of a (117) 70-foot-tall building looking across at another
building. Use the picture to answer the questions.
a. Find the distance from the bottom of the
building where you are standing to the top of the other building.
C
B
240
c
A
b. Find the measure of ∠A.
*8. Nature A tree casts a shadow of 25 feet along the ground. The angle from the
(117) ground to the top of the tree is 45°. How tall is the tree?
45°
25 feet
9. If $1100 is borrowed for 2 years at 9% simple interest, how much interest is paid? (116)
*10. Navigation A submarine begins diving from the water’s surface at an angle of 7°. (117) How far below the water’s surface is the submarine after it has traveled 3.4 miles?
x
7°
3.4 miles
*11. Generalize Explain the meaning of opposite leg and adjacent leg to an acute angle (117) in a right triangle.
_13 (tan A) = tan (
70
Lesson 117
801