Answer:
See below for answers
Explanation:
1st Problem:
Because the figure is a triangle, it's interior angles will add up to 180 always. Since it's a right triangle, we know one of the angles is 90, but we'll need to set up an equation to solve for x.
90+(2x-2)+(x+5)=180
2x-2+x+5=90
3x+3=90
3x=87
x=29
Therefore, B) 29, is the correct answer
2nd Problem:
Given side lengths of a, b, and c, if a+b<c, then it's a triangle. Since 8+8 is not less than 16, the sides do not make a triangle. The hypotenuse, c, must always be the longest length.
Therefore, A) Not a triangle, is the correct answer
3rd Problem:
To find angle x, we need the last interior angle of the triangle. Since the interior angles of a triangle add up to 180, we once again set up an equation to find the missing interior angle:
21+34+y=180
55+y=180
y=125
Since the missing interior angle is 125 degrees, it is supplementary to angle x, where supplementary angles add up to 180 degrees as well. So we would subtract 125 from 180 to get x. 180-125=55, so angle x is 55 degrees. Therefore, C) 55, is the correct answer.
4th Problem:
Again, use the Interior Angle Theorem to get x:
58+47+x=180
105+x=180
x=75
Therefore, A) 75, is the correct answer
5th Problem:
3,4,5 is a Pythagorean Triple, so it is a right triangle as 3^2+4^2=5^2. It is also scalene because none of the sides are equal to each other.
Therefore, B) Yes, scalene, is the correct answer