C) to protect landscapes and endangered species
You can usually tell the difference between a caldera and crater by studying <span>a feature's size and formation. In terms of size, a caldera is often relatively larger than ordinary craters. A caldera is so big that it causes explosive eruptions. In terms of formation, a caldera is a large depression caused when a magma chamber is emptied. A crater is a bowl-like formation at the top of volcanoes where lava comes out.</span>
Answer: 75
This is how I did it: We know that triangles add up to 180, so subtract the known angle from 180 and you'll get 150. Then divide 150 by 2 to find out the other two angles and you'll get 75.
180-30=150
150÷2=75
So the answer is 75
:)