Finding the Missing Angle or Side for Right Triangle Trigonometry

Find the trig ratios of B and complete the table.

a

b

c

15/17

8/17

15/8

How do you solve the for the missing leg of a right triangle when you have only the right angle and 2 of the sides?

• You use the sin trig ratio.

• You use the cos trig ratio.

• You use the tan trig ratio.

• You use Pythagorean theorem.

Label the sides of the triangle and choose the correct trig ratio

d

e

f

a

b

hyp

tan

adj

no info

sin

opp

cos

To find the missing side of a right triangle given 1 legs and the hypotenuse you will...

• Use Pythagorean theorem

• Plug in the 2 legs for a and b

• Square everything

• subtract

• Take the square root

Label the sides of the triangle and choose the correct trig ratio

b

d

e

f

a

tan

hyp

no info

sin

adj

cos

opp

Label the sides of the triangle and choose the correct trig ratio

d

e

f

a

g

hyp

opp

no info

adj

sin

tan

cos

Label the sides of the triangle and choose the correct trig ratio

d

e

f

a

c

no info

cos

hyp

opp

tan

adj

sin

Solve for the missing angle.

• 50.2

• 93.1

• 12.6

• 42.2

Find the measure of the missing angle.

• 49^o

• 52^o

• 41^o

• 33^o

Find the length of side y.

• 22.32 cm

• 36.5 cm

• 76.34 cm

• 87.76 cm