Answer:
y = -5x + 21
Step-by-step explanation:
perpendicular lines have slopes that are negative reciprocals.
The given line has a slope of 1/5, so the perpendicular line will have a slope of -5.
y = -5x + B
-4 = -5(5) + B
B = -4 + 25 = 21
y = -5x + 21
for a normal triangle its (bh)/2 but this is a right triangle so you multiply the two perpendicular sides and divide it by 2