Zen F. answered 09/24/20
Middle and High School Math Tutor
One angle of a triangle is twice as large as another. The third contains 5 degrees more than the larger of these. Find the smallest angle
......Okay given the sum triangle theorem....stated below from wikipedia.....
In a Euclidean space, the sum of angles of a triangle equals the straight angle (180 degrees, π radians, two right angles, or a half-turn). A triangle has three angles, one at each vertex, bounded by a pair of adjacent sides.
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One angle of a triangle is twice as large as another. The third contains 5 degrees more than the larger of these. Find the smallest angle
Let X be the first angle.......and Y be the second angle......and Z be the third angle......
X+Y+Z = 180 degrees
X = 2Y
Z = X + 5
.......the smallest angle is Y.......You now have 3 equations and 3 unknowns.......
....using substitution.....we have....
X + 1/2(X) + X+5 = 180.......NOW solve for X
2X + X + 2X + 10 = 360......Multiply both sides by 2.....removes the fraction for easy computing....
5X + 10 = 360.........subtract both sides by 10......
5X = 350
+
X = 70
NOW LETS CHECK.......IF X = 70...THEN Y=1/2(70)=35 Z = X + 5 = 70 + 5 = 75......
Is X + Y + Z = 180.......70 + 35 + 75 = 180.....that checks......so Y your smallest angle is 35