At what temperature do the centigrade and the fahrenheit thermometer record the equal temperature​

-40 °C

Key Takeaways: When Does Fahrenheit Equal Celsius? Celsius and Fahrenheit are two temperature scales. The Fahrenheit and Celsius scales have one point at which they intersect. They are equal at -40 °C and -40 °F.

diagram is missing, but i will try to explain your doubt.

answer:

amplitude is the maximum displacement or distance moved on a point of a vibrating body or wave measured from its equilibrium position.it is equal to half the length of vibration path.

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.