The given angles sum to less than 90°, so the remaining angle must be more than 90°. (The total of all angles is 180°.) Triangle ABC has an angle greater than 90°, so is obtuse. Since the triangles are similar, their corresponding angles are congruent. Hence ...
.. D. Triangle XYZ is obtuse.
The Gaia Theory was proposed. By the british.
Cogeneration is the process of taking a waste product or process and producing heat and generating electricity from it at the same time.
It could be collection of waste heat from the original generation of electricity or burning of biodiesel, ethanol or methane gas from sewer or cow dung. The only answer where electricity is using or creating heat and generating electricity power is C.