EASY QUESTION ABOUT GEOMETRY! POINTS ON A GRAPH

Here's the question:

Find PQ for P (2,7) and Q (-4,2). Round to the nearest tenth.

It's multiple choice so:

6, 5.4 , 7.8, -7.8

I'm confused I don't even know how to do this?? Thanks! Explain it to if you can thanks

Also here's an extra: the measure of the supplement (two angles with measures that have a sum of 180) of an angle is 30 less than four times the measure of the complement (2 angles with measures that have a sum of 90) of the angle. Find the measure of that angle:

Multiple choice: 130, 6, 40, 50.

I thought it was gonna be like...
90x4 = 360
360-30= 330
330- 180 = 150 < but 150 isn't a choice so please help?

Plot the points. PQ can be viewed as the hypotenuse of a right triangle with sides 5 and 6. The Pythagorean formula gives the length.

a² + b² = c²

5² + 6² = c²

25 + 36 = c²

61 = c²

c = 7.8


Let the supplement and complement of A be S and C, respectively.

A + S = 180

A + C = 90

S = 4C - 30

Solve second equation for C.

C = 90 - A

Substitute into third equation.

S = 4(90 - A) - 30

Plug that into first equation.

A + 4(90 - A) - 30 = 180

Simplify.

A + 360 - 4A - 30 = 180

330 - 3A = 180

- 3A = - 150

A = 50

distance² = (-4 - 2)² + (2 - 7)²
= (-6)² + (-5)²
= 36 + 25
= 61

distance = √61