(14. Triangle BCD is an isosceles triangle; this means that both angle C and angle D are congruent, this sets up quite a simple equation for us.
5x-19=2x+14 -2x -2x 3x-19=+14 +19 +19 3x=33 x=11
With this information, we can substitute the value of x into the equations representing the measure of the angles.
B=-13x-35 B=13(11)-35 B=143-35 B=108
C=5x-19 C=5(11)-19 C=55-19 C=36
Because C and D are congruent, they both equal the same amount. The angles of a triangle are all equal to 180 so add the three angles together to check your answer.
108+36+36=180
(15. Fifteen is fourteen in reverse, instead of angles you have to find the value of line segments. I won't go through the steps for this one because the steps are the same for this one.
