Answer:
B) 29
Step-by-step explanation:
Given:
AC= 58
Point D and E are the midpoints of side AB and BC Respectively.
Solution:
According to Midpoint theorem which states:
"The segment joining two sides of a triangle at the midpoints of those sides is parallel to the third side and is half the length of the third side."
DE=
AC
DE=
Hence length of DE is 29.
Answer:
158.76 cm²
Step-by-step explanation:
Quadrilateral ABCD is composed of 2 right triangles
Construct the line BD, then
Δ ABD and Δ BCD are the 2 right triangles.
The area (A) of a triangle is calculated using
A = bh ( b is the base and h the perpendicular height )
Δ ABD with b = 18 and h = 7.5
A = × 18 × 7.5 = 9 × 7.5 = 67.5 cm²
Δ BCD with b = 15.6 and h = 11.7
A = × 15.6 × 11.7 = 7.8 × 11.7 = 91.26 cm²
Thus
area of ABCD = 67.5 + 91.26 = 158.76 cm²
The mean of this test will be 57.
<h3>What is Standard Deviation and Mean?</h3>
A standard deviation (or σ) is a measure of how dispersed the data is in relation to the mean.
The mean can be used to get an overall idea, or picture, of the data set.
Let Mean be 'm'
and standard deviation=
So, m-2=49
and, m + =61
Solving the above two equation we get
Now, m= 61-
= 61-4
= 57
So , the mean of this test will be =57
Learn more about mean and standard deviation here:
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