Question 957519
A=area=360 sq m; h=altitude; b=base=2h+18m
{{{A=(1/2)bh}}} Substitute for b.
{{{360m^2=(1/2)(2h+18)(h)}}} Multiply each side by 2.
{{{720m^2=2h^2+18h}}} Subtract 720 m^2 from each side
{{{0=2h^2+18h-720m^2}}}*[invoke quadratic "h", 2, 18, -720 ]
h=15m ANSWER: The altitude of the triangle is 15 meters.
CHECK:
b=2h+18m=2(15m)+18m=48m The base of the triangle is 48 meters.
A=1/2bh
360sq m=1/2(48m)(15m)
360 sq m=360 sq m