What is the slant height of the pyramid to the nearest 10th 15.5mm
13.9mm
12.5mm
19.0mm

12.5mm

Step by step explanation:
The slant height is just the hypotenuse of the triangle where the height and base are the legs. The height is 12 and the base is 7. We only use half of the base which is 3.5. Using the Pythagorean theorem, 12^2+3.5^2=c^2.
It simplifies to 144+12.25=c^2. Then, 156.25=c^2. Find the radical of 156.25 and you will get c=12.5.
The slant height is 12.5