9514 1404 393
Answer:
x = 78
Step-by-step explanation:
The base angles of an isosceles triangle are congruent, so the sum of angles is ...
x° +x° +24° = 180°
2x +24 = 180 . . . . . collect terms
x + 12 = 90 . . . . . . . divide by 2
x = 90 -12 . . . . . . . . subtract 12
x = 78
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<em>Additional comment</em>
The base angle of an isosceles triangle is always the complement of half the third angle. That angle's bisector is an altitude, so divides the isosceles triangle into two congruent right triangles.