Question

An isosceles triangle with angles b and c having the same measure is shown. Find the measure of each angle whose degree measure is represented with variables. A= x+ 7y+41,B= 2y+13,C=6x+15

Answer 1

Answer:

A = 114°, B = C = 33°

Step-by-step explanation:

The triangle relationships let you write two equations:

A+B+C = 180

B=C

Substituting the expressions for A, B, and C, you have ...

(x+7y+41) +(2y+13) +(6x+15) = 180

7x +9y +69 = 180

7x +9y = 111

And the second equation gives ...

(2y+13) = (6x+15)

6x -2y =-2

3x -y = -1

Now, we can add 9 times this second equation to the first to eliminate the y-variable.

(7x +9y) +9(3x -y) = (111) +9(-1)

34x = 102

x = 3

Then the angle measures are ..

B = C = 6·3+15 = 33

A = 180 -2·33 = 114

The angles in the triangle are (A, B, C) = (114°, 33°, 33°).