Circle O is shown. 2 secants intersect at a point outside of the circle to form angle 1. The first arc formed is d, and the second arc formed is b. Arcs a and c are the other 2 arcs outside of the secants.

Which equation is correct regarding the measure of ∠1?

m∠1 = One-half(a – c)

m∠1 = One-half(a + c)

m∠1 = One-half(b – d)

m∠1 = One-half(b + d)

(b) 240

step-by-step explanation:

first, we use the pythagorean formula using the given side lengths to find x. then we use x to find the side lengths. then we add the side lengths to find the perimeter.

pythagorean theorem formula:

a^2 + b^2 = c^2

(x - 20)^2 + (x - 40)^2 = x^2

x^2 - 40x + 400 + x^2 - 80x + 1600 = x^2

x^2 -120x + 2000 = 0

(x - 100)(x - 20) = 0

x - 100 = 0 or x - 20 = 0

x = 100 or x = 20

we see that the solution x = 20 must be discarded because it will give a negative side length and a side length of 0. the only valid solution is x = 100.

perimeter = sum of the lengths of the sides

perimeter = x + x - 20 + x - 40

perimeter = 3x - 60

replace x with 100.

perimeter = 3(100) - 60

perimeter = 300 - 60

perimeter = 240

i believe it is 0.1m because the measurement of 30.4m limits how precise you can be

you can only be as precise as the least precise measurement

i believe so, according to my "strange" way of figuring out weird math problems like this.