A trapezoid has an area of 18 square miles. The bases are 5 miles and 7 miles. What is the height of the trapezoid?

Area (trapezoid) = (base ₁+base₂) * height/2

Area=18 miles²

base ₁=5 miles

base ₂=7 miles

18 miles² = (5 miles+7 miles) * height / 2

18 miles² * 2 = (12 miles) * height

12 miles * (height) = 36 miles²

height=36 miles² / 12 miles=3 miles.

Solution: heigth=3 miles.