234k views
4 votes
5) If AABC ASDF and mA = 3x + 5, mzB = 5x-9 and mz5= 1.5x + 17. Find mzB.

A. mzB = 7°
8. m2B-8"
C. mzB 26°
D. mzB 31°

SHOW WORK!!!!!!!

User Bill Reiss
by
7.6k points

1 Answer

1 vote
We can start by using the fact that AABC is an isosceles triangle to find the measure of angle AAB:

mAA + mAB + mAC = 180 (sum of angles in a triangle)

Since AABC is isosceles, we know that angle AAB is congruent to angle AAC:

mAA = mAC

Substituting this into the equation above, we get:

mAA + mAB + mAA = 180

2mAA + mAB = 180

Simplifying, we get:

mAB = 180 - 2mAA

Next, we can use the given angle measures to set up an equation involving angle ABZ:

mABZ = mAB - m5 - mZB

Substituting the given angle measures, we get:

mABZ = (180 - 2mAA) - (1.5x + 17) - (5x - 9)

Simplifying and collecting like terms, we get:

mABZ = 166 - 6.5x - 2mAA

We still need to find the measure of angle AAB, which we can do by using the equation for mA:

mA = 3x + 5

Since AABC is isosceles, we know that angle AAB is congruent to angle AAC, which means that mAAB = mAAC. Using the equation for mA, we can write:

mAAB = mAAC = 3x + 5

Now we can substitute this into the equation for mABZ:

mABZ = 166 - 6.5x - 2(mAAB)

Substituting mAAB, we get:

mABZ = 156 - 12.5x

Now we can solve for x by using the fact that mABZ + mZB + mzB + mz5 = 360 (since they form a quadrilateral). Substituting the expressions for mABZ, mZB, mzB, and mz5, we get:

156 - 12.5x + 5x - 9 + 1.5x + 17 = 360

Simplifying and solving for x, we get:

-5.5x = 196

x = -36

However, this value of x does not make sense since the measures of angles in a triangle and quadrilateral must be positive. Therefore, there is no solution that satisfies the given conditions and the answer is "no solution".
User Sebin Sunny
by
8.1k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories