**The basis to respond this question are:**
**1) Perpedicular lines form a 90° angle between them.**

**2) The product of the slopes of two any perpendicular lines is – 1.**

So, from that basic knowledge you can analyze each option:

**a.Lines s and t have slopes that are opposite reciprocals.**

**TRUE. Tha comes the number 2 basic condition for the perpendicular lines.**

slope_1 * slope_2 = – 1 => slope_1 = – 1 / slope_2, which is what opposite reciprocals means.

b.Lines s and t have the same slope.

FALSE. We have already stated the the slopes are opposite reciprocals.

**c.The product of the slopes of s and t is equal to -1**

**TRUE: that is one of the basic statements that you need to know and handle.**

d.The lines have the same steepness.

FALSE: the slope is a measure of steepness, so they have different steepness.

e.The lines have different y intercepts.

FALSE: the y intercepts may be equal or different. For example y = x + 2 and y = -x + 2 are perpendicular and both have the same y intercept, 2.

f.The lines never intersect.

FALSE: perpendicular lines always intersept (in a 90° angle).

**g.The intersection of s and t forms right angle.**

**TRUE: right angle = 90°.**

h.If the slope of s is 6, the slope of t is -6

FALSE. – 6 is not the opposite reciprocal of 6. The opposite reciprocal of 6 is – 1/6.

**So, the right choices are a, c and g.**