Math Problem Statement

Solve the following problems. Draw the figure for each item.

  1. The vertices of a triangle are at (1, 7), (6, -1) and (0, 3). Find the coordinates of the midpoints of the sides.

  2. The segment from (-1, 4) to (2, 2) is extended three times its own length. Find the terminal point.

  3. The segment joining (2,-4), (2, 3) is divided into two segments, one of which is three fourths as long as the other. Find the point of division. Ans. (6, 0) and (5,-1)

  4. The circle with its center at (4,-2) has one end of the diameter at (7, 2). Find the coordinates of the other end of this diameter.

5.A person 6 ft. tall is standing near a street light so that he is 4/10 of the distance form the pole to the tip of his shadows. How high above the ground is the light bulb?

Solution

Let's solve each problem step by step and draw the required figures.

Problem 1: Midpoints of the Sides of a Triangle

Vertices of the triangle: (1, 7), (6, -1), and (0, 3).

To find the midpoints of the sides of the triangle, we'll use the midpoint formula:

Midpoint=(x1+x22,y1+y22)\text{Midpoint} = \left( \frac{x_1 + x_2}{2}, \frac{y_1 + y_2}{2} \right)

Calculations:

  1. Midpoint of side between (1, 7) and (6, -1):

    (1+62,7+(1)2)=(72,62)=(3.5,3)\left( \frac{1 + 6}{2}, \frac{7 + (-1)}{2} \right) = \left( \frac{7}{2}, \frac{6}{2} \right) = (3.5, 3)

  2. Midpoint of side between (6, -1) and (0, 3):

    (6+02,1+32)=(62,22)=(3,1)\left( \frac{6 + 0}{2}, \frac{-1 + 3}{2} \right) = \left( \frac{6}{2}, \frac{2}{2} \right) = (3, 1)

  3. Midpoint of side between (0, 3) and (1, 7):

    (0+12,3+72)=(12,102)=(0.5,5)\left( \frac{0 + 1}{2}, \frac{3 + 7}{2} \right) = \left( \frac{1}{2}, \frac{10}{2} \right) = (0.5, 5)

Midpoints: (3.5, 3), (3, 1), and (0.5, 5).

Problem 2: Extended Line Segment

Segment endpoints: (-1, 4) and (2, 2).

The length of the line segment is extended three times its own length.

  1. Length of the segment: Using the distance formula:

    Length=(2(1))2+(24)2=(2+1)2+(2)2=9+4=13\text{Length} = \sqrt{(2 - (-1))^2 + (2 - 4)^2} = \sqrt{(2 + 1)^2 + (-2)^2} = \sqrt{9 + 4} = \sqrt{13}

  2. Direction vector from (-1, 4) to (2, 2):

    (2(1),24)=(3,2)(2 - (-1), 2 - 4) = (3, -2)

  3. Extending the segment: Scale the direction vector by 3:

    (3×3,3×2)=(9,6)(3 \times 3, 3 \times -2) = (9, -6)

  4. Finding the terminal point:

    (2,2)+(9,6)=(11,4)(2, 2) + (9, -6) = (11, -4)

Terminal Point: (11, -4).

Problem 3: Dividing the Segment into Two Segments

Endpoints: (2, -4) and (2, 3).

Division ratio: One segment is 34\frac{3}{4} of the other.

  1. Total length of the segment:

    Length=3(4)=7\text{Length} = |3 - (-4)| = 7

  2. Finding the ratio: Let xx be the length of one segment and 34x\frac{3}{4}x be the other.

    x+34x=7    74x=7    x=4x + \frac{3}{4}x = 7 \implies \frac{7}{4}x = 7 \implies x = 4

    The two segments are 4 and 3 units long.

  3. Point of division:

    From (2, -4) to (2, 3), the point is 4 units above (2, -4):

    (4+4)=0    (2,0)(-4 + 4) = 0 \implies (2, 0)

Point of Division: (2, 0).

Problem 4: Finding the Other End of a Diameter of a Circle

Center of circle: (4, -2).

One endpoint of the diameter: (7, 2).

  1. Midpoint (center) formula:

    Center=(x1+x22,y1+y22)\text{Center} = \left( \frac{x_1 + x_2}{2}, \frac{y_1 + y_2}{2} \right)

  2. Setting up equations:

    4=7+x2,2=2+y24 = \frac{7 + x}{2}, \quad -2 = \frac{2 + y}{2}

    Solving:

    8=7+x    x=1,4=2+y    y=68 = 7 + x \implies x = 1, \quad -4 = 2 + y \implies y = -6

Other Endpoint: (1, -6).

Problem 5: Height of the Light Bulb

Person's height: 6 ft.

Ratio: 410\frac{4}{10} of the distance from the pole to the tip of the shadow.

Using similar triangles:

  1. Let xx be the height of the pole, and dd be the distance of the shadow.

  2. From the ratio:

    6=410×x6 = \frac{4}{10} \times x

    Solving for xx:

    6×104=x    x=156 \times \frac{10}{4} = x \implies x = 15

Height of the Light Bulb: 15 ft.


Would you like a detailed explanation or any drawings for these solutions? Here are some related questions:

  1. How do you find the centroid of a triangle given its vertices?
  2. What is the formula for finding the length of a segment given two points?
  3. How do you calculate the slope of a line between two points?
  4. How can you determine if three points are collinear?
  5. What is the equation of a circle given its center and radius?

Tip: When solving geometric problems, drawing figures can help visualize and simplify the problem!

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Math Problem Analysis

Mathematical Concepts

Geometry
Coordinate Geometry
Proportions
Ratios
Distance Formula
Midpoint Formula
Extended Segments
Similar Triangles

Formulas

Midpoint formula: ( (x1 + x2) / 2, (y1 + y2) / 2 )
Distance formula: sqrt( (x2 - x1)^2 + (y2 - y1)^2 )
Proportions and Ratios
Similar triangles for shadow problems

Theorems

Properties of line segments and midpoints
Pythagorean theorem for distance calculation
Properties of similar triangles

Suitable Grade Level

Grades 9-12