A trapezoid is a quadrilateral with one pair of parallel lines
A trapezoid is a quadrilateral with one pair of parallel lines.
The two parallel lines are called the bases
The two non parallel lines are the legs.
Adjacent Angles of Trapezoid
The angles on the same side of a leg
are called adjacent angles such as
MLO are supplementary
. For the same reason,
NOL are supplementary.
Use adjacent angles theorem to calculate m
MLO = 180-124 = 56°
Find the value of x in the trapezoid below, then determine the measure of angles
What is wrong with trapezoid LMNO pictured below? (Explain why LMNO cannot be a trapezoid based on the information provided)
Area of Trapezoid
- Area = 7 × ½(4 +8)
- 7 × ½(12)
- 7 ×6
- 42 square feet
Midsegment of Trapezoid
The midsegment of a trepzoid is
- parallel to both bases
- has length equal to the average of the length of the bases
Use the midsegment theorem to determine the length of midsegment ON
To calculate the length of the midsgement find the average of the bases
length of midsegment= (6+4)/2 = 5
Quick REVIEW of Midpoint.
The midpoint of the red segment pictured on the left is the point (A, 2b). The most important thing to remember is that a midpoint bisects a line (cuts a line into two equal halves).
The midsegment of a trapezoid is the segment that joins the midpoints of the nonparallel sides of a trapezoid.
In the trapezoid below, the midpoints of the non-parallel sides are points S and V. The midsegment is the red line segment from S to V.
The midsegment below can be found by
- calculating the lengths of the bases
- 35-16 = 9 (lenght of upper base)
- 45-0 =45 (length of lower base)
- calculating the sum of the bases
- Dividing the sum by 2
The length of the midsegment is 26.5
What is the length of midsegment SV
in the trapezoid below?
Length of top base = 17-8 = 9
Length of bottom base= 20-0 =20
Sum of bases = 9 + 20 = 29
Divide sum of bases by 2 = ½(29) = 14.5
Therefore, the midsegment SV is 14.5 in length.
Is the reg segment below a midsegment?
It is not a true midsegment because its length does not
equal half the sum of the lengths of the bases.