Answer
a. $2x-1$
b. $\frac{1}{2}(2x-1)\times y$ where y is the height
c. $248$
Work Step by Step
The height of the triangle is 1 cm less than twice the length of the base where x= the length of the base
a. the expression would be $2x-1$
b. $\frac{1}{2}(2x-1)\times y$ where y is the height
c. $x=16$ so plug that into $2x-1$ to find the height
$2(16)-1$ so the height would be $31$
Now multiply the base and height $16\times31$
Since it is a triangle you must divide by 2 so the answer would be $248$