What is the measure of angle 1?

Which best explains why this triangle is or is not a right triangle?

Arefrigeration system at your company uses temperature sensors fixed to read celsius (°c) values, but the system operators in your control room understand only the fahrenheit scale. you have been asked to make a fahrenheit (°f) label for the high temperature alarm, which is set to ring whenever the system temperature rises above –10°c. what fahrenheit value should you write on the label

Two times a number plus three times another number equals 4. three times the first number plus four times the other number is 7. find the numbers