Problem 4
Note the markings at the top indicate that angle y represents half the angle BAC. In other words, we need 2 copies of angle y to make up angle BAC.
So we know that angle BAC = 2y
Due to the fact that triangle ABC is isosceles, we know that base angles B and C are congruent to 47.
Focusing on triangle ABC we have
So,
A+B+C = 180 .... for any triangle, the angles always add to 180
2y+47+47 = 180
2y+94 = 180
2y = 180-94
2y = 86
y = 86/2
y = 43
Turn your attention to triangle ABD.
Here we have
- angle A = y = 43
- angle B = 47
- angle D = x
We'll use the same idea as above, that all angles add to 180, to get...
A+B+D = 180
y+47+x = 180
43+47+x = 180
x+90 = 180
x = 180-90
x = 90
Answer: D) x = 90, y = 43
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Problem 5
Let x be the angle formed by the diagonal sides and the horizontal ground. This is considered the base angle because this triangle is isosceles.
We have two base angles x and the third angle up top is 34
x+x+34 = 180
2x+34 = 180
2x = 180-34
2x = 146
x = 146/2
x = 73
Answer: C) 73