A convex quadrilateral has exterior angle measures, one at each vertex, of 5b+7°, 34b–33°, b+36°, and 37b–35°. What is the value of b?

2 Answers
Feb 25, 2018

b=5

Explanation:

"the " color(blue)"sum of the exterior angles "=360^@

"the sum of the 4 exterior angles is then"

5b+7+34b-33+b+36+37b-35=360

rArr77b-25=360

"add 25 to both sides"

77bcancel(-25)cancel(+25)=360+25

rArr77b=385

"divide both sides by 77"

(cancel(77) b)/cancel(77)=385/77

rArrb=5

b = 5^@.

Explanation:

As soon as I read the question and it was talking about exterior angles I wrote the values above are equal to 360^@.

5b+7 + 34b - 33 + b + 36 + 37b - 35 = 360^@

It equals 360^@ as exterior angles add up to 360^@ as it goes all around a point. So when you simplify the values give you get

77b - 25 = 360

77b = 360 + 25

77b= 385

Divide both sides by 77 to isolate b

b= 5