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Lesson # 26 Distance from a Point to a Line. Recall that to find the area of a triangle on a Cartesian plane It takes several steps…. B. A. C. H. Find slope AC. 2. Slope BH is the negative reciprocal. 3 . Find eq of line BH using B and slope in y = ax+b.
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Lesson #26 Distance from a Point to a Line
Recall that to find the area of a triangle on a Cartesian plane It takes several steps…. B A C H Find slope AC 2. Slope BH is the negative reciprocal 3. Find eq of line BH using B and slope in y=ax+b 4. Find eq of line AC using A and slope in y=ax+b Find POI by letting y1=y2 6. Use distance formula on BH and on AC There has got to be a better way?! 7. Use A=bh/2 to find the area
Eg. 1 Imagine Molly needs to get to safety The path with shortest distance from a point to a line meets the line at aright angle. Beach Distance Formula Where ax+by+c=0 is the eq for the line in general form. and (h,k) is the coordinate of the point.
1. Find the eq in functional form A(-3,4) C(4,3) k h a b c Beach B(-1,-2) 2. Use D(l,p) Therefore the shortest path to safety is 6 m.
Eg. 2 Find the shortest distance to land 1. Find the eq in general form A(-4,-1) k h a b c B(4,-2) 2. Use D(l,p) Therefore the shortest path to land is 6.71 km
Homework Pg. 156 #1-5