Yes LMN is a right triangle .
B: ray
Rays are a linear formation that start at a point and continue forever in a direction. The photo shows a point on one end, and an arrow on the other indicating that it starts at the point and continues forever past the arrow.
First one is 12^2
second one is 1
Lateral surface area = (23×12.04)+(23×8)+(23×9)
= 276.92 + 184 + 207
=667.92
= 668m²
Total surface area = 668 + 1/2(2×8×9)
= 668 + 72
= 740m²