Y = 1/3x ? 6....slope here is 1/3. A perpendicular line will have a negative reciprocal slope. All that means is " flip " the slope and change the sign. So our perpendicular line will have a slope of -3 (see how I flipped 1/3 and changed the sign)
y = mx + b
slope(m) = -3
(-9,12)...x = -9 and y = 12
now we sub and find b, the y int
12 = -3(-9) + b
12 = 27 + b
12 - 27 = b
-15 = b
so ur perpendicular equation is : y = -3x - 15
this depends. you can measure angles in real life with a protractor or just use your eye. let us start with the protractor. place the midpoint of a protractor on the vertex of the angle and make sure it lines up to 0. on the other side read the degrees (make sure everything aligns). without a protractor you can use the Sine Formula and measure the lines.
Area A Output: 2, 4, 6, 8
Perimeter P Output: 6, 8, 10, 12
Explanation: Just replace the x with the inputs and then solve.