Problem
GEO-B1-M04-P010 Find a Base of a Trapezoid
#10
★★☆☆☆ Level 2 of 5
In trapezoid \(ABCD\), bases \(AD\parallel BC\). The midline is \(14\), and the smaller base is \(BC=8\). Find \(AD\).
Write the formula \(MN=\frac{AD+BC}{2}\).
Let \(MN\) be the midline. Then \(14=\frac{AD+8}{2}\). Hence \(AD+8=28\), so \(AD=20\).
A numerical task after proof tasks: useful for confident use of the formula.