Given an MNKP trapezoid, angle M = 45 degrees, angle P = 30 degrees, MN = 8cm, KP = 10cm
Given an MNKP trapezoid, angle M = 45 degrees, angle P = 30 degrees, MN = 8cm, KP = 10cm, NK = 5cm Find the middle line.
From the vertices obtuse angle N and K, we omit two heights NH and KB.
In a right-angled triangle MNH, by the Pythagorean theorem, we define the length of the leg MN.
MH = MN * Cos450 = 8 * √2 / 2 = 4 * √2 cm.
In a right-angled triangle KPV, according to the Pythagorean theorem, we determine the length of the leg PB.
РВ = КР * Cos300 = 10 * √3 / 2 = 5 * √3 cm.
The quadrilateral NKVN is a rectangle, since NP is parallel to HB as the base of the trapezoid, and NH is parallel to KB as the height of the trapezoid, then HB = NK = 5 cm.
Let us determine the length of the base of the MP. МР = НВ + МН + РВ = 4 * √2 + 5 + 5 * √3 ≈ 19.32 cm.
Determine the length of the midline of the trapezoid.
SD = (NK + MP) / 2 = (5 + 19.32) / 2 = 12.16 cm.
Answer: The length of the middle line is 12.16 cm.