Answer: Width will be 10 inches
and height will be 14 inches.
Explanation:
Since we have given that
The are of the triangular display case is 70 sq. in.
Let the width of the base be x
Let the height of the base be 2x-6
As we know the formula for " Area of triangle " i.e.

According to question,

Since width can't be negative so, we take width = 10 inches
And height is given by

Hence, width will be 10 inches
and height will be 14 inches.