Sudut A sebesar 20° dan sudut B sebesar (85-x)° saling berpenyiku. Besar sudut B yaitu .... °.
视频信息
答案文本
视频字幕
We have a problem about complementary angles. Angle A measures 20 degrees, and angle B measures 85 minus x degrees. Since these angles are complementary, they must add up to 90 degrees. Let's visualize this relationship and solve for the value of angle B.
Now let's set up the equation. Since angles A and B are complementary, they must sum to 90 degrees. We substitute our known values: 20 degrees plus 85 minus x degrees equals 90 degrees. Simplifying, we get 20 plus 85 minus x equals 90, which gives us 105 minus x equals 90.
Let's solve for x step by step. Starting with 105 minus x equals 90, we subtract 105 from both sides to get negative x equals negative 15. Multiplying both sides by negative 1, we find that x equals 15.
Now we can find the measure of angle B. We substitute x equals 15 into the expression for angle B. Angle B equals 85 minus 15, which gives us 70 degrees. Let's verify our answer: 20 degrees plus 70 degrees equals 90 degrees, confirming that our solution is correct.
In conclusion, we have successfully solved the problem. The measure of angle B is 70 degrees. This makes sense because when we add angle A, which is 20 degrees, to angle B, which is 70 degrees, we get exactly 90 degrees, confirming that these angles are indeed complementary.