Answer
Find out the percent error in Annie's estimate .
To prove
Formula
As error = approx value - exact value
As given
Annie estimates that the height of a bookcase is 78.25 in.
The actual height is 75.50 in.
approx value = 78.25 in.
actual value = 75.50 in.
error = 78 .25 - 75 .50
= 2.75
put in the formula
Percentage error = 3.64 % (approx)
Therefore the Percentage error be 3.64 % (approx).
Here a right angled triangle given. We know that one angle of a right angled triangle is 90°.
As the sum of three angles of a triangle is 180°, so we can say the sum of other two angles of a right angled triangle is (180-90)° = 90°.
Here in the figure the other two angles given and
. Sum of these two angles is 90°.
So we can write the equation as,
We have to remove the parenthesis now.
Now we will add the like terms. Here x and 2x are like terms. By adding them we will get,
To solve it for x, now we have to move 15 to the other side by subtracting it from both sides.
Now to get x, we have to move 3 to the other side, by dividing it to both sides.
We have got the required value of x.
The solution is x= 25.
