Determine whether the following number sentences are true or false.
a. 4+8=10+5
b. 1/2+5/8=1.2−0.075
c. (71·603)·5876=603·(5876·71)
d. 13×175=13×90+85×13
e. (7+9)²=7²+9²
f. =3.141
g. √(4+9)=√4+√9
h. 1/2+1/3=2/5
i. 1/2+1/3=2/6
j. 1/2+1/3=5/6
k. 3²+4²=7²
l. 3²×4²=12²

A3-dimensional figure has a square base and 4 lateral faces that meet at a point. explain the difference between the cross sections when a slice is made perpendicular to the base through the vertex, and when a slice is made perpendicular to the base and not through the vertex