Question 451004
b=.5h, A=196 mm^2
.5bh=A
.5*.5h*h=196
.25h^2=196
h^2=784
h=28 mm
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Ed
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PS:
196=1/2(1/2h)(h)  can't we multiply both sides by 2 to get...? 
NO we can't! You can cancel off one 1/2 only when multiplying or dividing. Also (1/2h) is incorrect. (h/2) is correct and easiest. Also h(1/2) is correct.
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I'm glad to help someone who shows their work like you have.