Answer:
He should have multiplied both numbers by 100
Step-by-step explanation:
Given
See Attachment for given
Required
What's Chen error
Chen error is at step 2 where he changed 0.9 to 9.
Any changes made on the divisor must also be made on the dividend
He got 9 by multiplying 0.9 by 10;
So, his mistake is that he should have multiplied both numbers by the same number.
From the list of given options, the option that best answer this question is He should have multiplied both numbers by 100
In geometry, it is always advantageous to draw a diagram from the given information in order to visualize the problem in the context of the given.
A figure has been drawn to define the vertices and intersections.
The given lengths are also noted.
From the properties of a kite, the diagonals intersect at right angles, resulting in four right triangles.
Since we know two of the sides of each of the right triangles, we can calculate their heights which in turn are the segments which make up the other diagonal.
From triangle A F G, we use Pythagoras theorem to find
h1=A F=sqrt(20*20-12*12)=sqrt(256)=16
From triangle DFG, we use Pythagoras theorem to find
h2=DF=sqrt(13*13-12*12)=sqrt(25) = 5
So the length of the other diagonal equals 16+5=21 cm
