Solve Quadratic Equations Using the Quadratic Formula · Exercise 42

An architect is designing a hotel lobby. She wants to have a triangular window looking out to an atrium, with the width of the window 6 feet more than the height. Due to energy restrictions, the area of the window must be 140 square feet. Solve the equation $\frac{1}{2}{h}^2+3h=140$ for $h$, the height of the window.

Its source prints no answer for this problem, so there's nothing to check against.

OpenStax, Elementary Algebra 2e · §10.3 Solve Quadratic Equations Using the Quadratic Formula · Exercise 42