If the measure of 1 is x and the measure of <2 is x+50, what is the measure of <4? A. 50
B. 55
C. 110
D. 115

Measure of angle 4 is 115°

Step-by-step explanation:

First, we want to find the measure of angle 2, because the measure of angle 2 is equal to angle 4. When 2 straight lines cross each other, the angles formed are always equal to the angle right across from it.

Find angle 2 by setting up an equation:

This is basically saying that angle 1 plus angle 2 equals 180°. In a half turnaround, the angle is 180°. Angle 1 and 2 make up a half turnaround.

Solve the equation:

Combine the 2 x's to get 2x.

Subtract 50 from both sides.

Divide both sides by 2.

Since x=65, plug 65 into x in the measure of angle 2 (x+50).

65+50=115.

Since Angle 2 is equal to angle 4, angle 4 is also 115.

256π units²   (answer b)

step-by-step explanation:

the formula for the surface area of a sphere of radius r

is             a = 4πr²

and so, if r = 8 units, then the surface area is:

a = 4π(8 units)² = 256π units²   (answer b)