Which statement correctly describes the diagram? Help it’s 8th grade 3x ams and I really need help ASAP , I already failed twice and this is my LAST attempt

Urgent? will give brainliest given that the blue triangle is a right triangle, which expression correctly gives the area of the red square? a) a2 + b2 b) a2 - b2 c) a2 - c2 d) c2 - a2