Which one should I use

Pythagorean Theorem and Sine

Step-by-step explanation:

you could use pythagorean theorem to find the 3rd side, then use inverse sine of c.

Using the equation a2 + b2 = c2

Subtract 13squared from 5squared

169-25

then take the square root of the answer- which is 12

then do the inverse of sine

that should give you the missing angle

table 3 represents a direct variation function. : )

60

step-by-step explanation:

every triangle measures a total of 120 degrees. you have to find angle c. we know that isosceles triangles angles are equal. 60 degrees plus 60 degrees gives you 120.