Please answer correctly

No it's not compulsory.

Step-by-step explanation:

If the ratio of sides are given then that can also help you find angle. Not only that if the relationship between the perpendicular and base are given then you can find angle

if im not mistaking its

step-by-step explanation:  

in 2010, the population of the state of california is 37.29 × 10⁶

step-by-step explanation:

population of los angeles = 3.79 × 10⁶

population of california = 9.84 × population of los angeles

                                        = 9.84 × 3.79 × 10⁶

                                        = 37.2936 × 10⁶

                                        = 37.29 × 10⁶

∴ in 2010, the population of the state of california is 37.29 × 10⁶