The area of a parallelogram is 276 cm2. the sum of its bases is 46 cm. each slanted side measures 13 cm. what is the height? 12 cm 13 cm 23 cm 46 cm

The formula for the area of a parallelogram is the same as that for the area of a rectangle:  A = bh, where b and h are the base length and height respectively.  If the area of the parallelogram in question is 276 cm^2 and we divide this by 23 cm (which is half of the sum of its bases, or half of 46  cm), we get h = 12 cm.

The height of the parallelogram is 12 cm.

Note that dropping a height (line) from either of the upper two corners of the parallelograph forms a triangle with hypotenuse 13 cm, height 12 cm and base 5 cm.