If two lines intersect and form 4 right angles, then
a.the lines are parallel
b.the lines are perpendicular
c.the angles are complementary
d.the lines are not coplanar

I believe the correct answer from the choices listed above is option B. If two lines intersect and form 4 right angles, then the lines are perpendicular.  The property of being perpendicular(perpendicularity) is the relationship between two lines which meet at a right angle (90 degrees).

B.the lines are perpendicular

Good luck!!

All you have to do in this problem, is know what s is, we find this by using the equation: s+8+2s+s=84 (we use 84 because it is the perimeter of the triangle.

Perimeter= 84 inches

1st side: 19

2nd side: 19+8=27

3rd side: 2*19=38