How does magma form at divergent tectonic plate boundaries?

Sources are from NationalGeographic.org

"Decompression melting involves the upward movement of Earth's mosty-solid mantle. ... Decomposition melting often occurs at divergent boundaries, where tectonic plates separate. The rifting movement causes the buoyant magma below to rise and fill the space of the lower pressure. The rock then cools into new crust."

I got this from NationalGeographic.org

"Decompression melting involves the upward movement of Earth's mosty-solid mantle..."The rifting movement causes the buoyant magma below to rise and fill the space of the lower pressure. The rock then cools into new crust."
I hope this helps you!!!:)

Answerweathering;

In a right-angled triangle: 1- the hypotenuse is the longest side2- we can apply pythagorean rule which states that: (hypotenuse)^2 = (side1)^2 + (side2)^2for the given triangle,longest side is 15 cm  side1 = 9 cmside2 is 12 cm  to check whether the triangle is right-angled or not,compare (15)^2 to the summation of (9)^2 and (12)^in other words, compare 225 to the summation of 81 and 144if they are both equal, then the triangle is right-angles, otherwise, it is not.you haven't provided the diagram showing her work, so i cannot tell the choice. however, apply my explanation to the question you have.