Algebra 1 Common Core Student Edition, Grade 8-9

Lesso n Ch eck

Do y o u k n o w H OW?

Find each trigonometric ratio for A
angle A in the triangle at the right.
6

1. sin A 2. cos A 3. tan A
   c 8 e
   Solve using trigonometric ratios.


2. A right triangle has a 40° angle. The h y p o ten u se is
   10 cm long. W hat is th e length of th e side opposite
   the 40° angle?


3. A right triangle's legs are 7 in. an d 24 in. long. W hat is
   the m easure of th e angle opposite the 24-in. leg?

Do yo u UN DERSTAND? ^ PRA O TCES

6. Vocabulary D escribe th e difference b etw een finding

th e sine of an angle an d th e cosine of an angle.

@ 7. Error Analysis In a right

triangle, th e h ypotenuse

is 5 in. long, a n d th e side

opposite LA is 4.5 in.

long. A s tu d en t found the

measure of LA as shown

on th e calculator screen

at th e right. D escribe an d

correct th e stu d e n t’s error.

Pr act i ce an d Pr o b l em - So l v i n g Ex er ci ses

Practice For A FGH and ALMN, find the value of each expression.

MATHEMATICAL

PRA CTICES

8. sinF 9. cosF 10. tan G

11. c o sL 12. tan M 13. sin M 5


12. tanF 15. sin G 16. tanF H

Find the value of each expression. Round to the nearest ten-thousandth.

17. sin 10° 18. tan 25°


18. cos 85° 20. tan 12°


19. sin 70° 22. cos 22°


20. sin 71° 24. ta n 30°

See Problem 1.

M 1 5 A/

n

Find the value of x to the nearest tenth.

25.

28.

25

See Problem 3.

\ X

1 41°\

/iF r /3 6 ° r

56 29

c

Po w er A lg eb r a.co m | Lesso n 10- 6 Tr i g o n o m e t r i c Rat i o s^649