Photo AI

In the triangle ABC shown below: |CAB| = 90°, |AX| = 4 cm, |AY| = 3 cm, and |AX| : |XB| = 1 : 2 - Leaving Cert Mathematics - Question b - 2018

Question icon

Question b

In-the-triangle--ABC-shown-below:--|CAB|-=-90°,-|AX|-=-4-cm,-|AY|-=-3-cm,--and-|AX|-:-|XB|-=-1-:-2-Leaving Cert Mathematics-Question b-2018.png

In the triangle ABC shown below: |CAB| = 90°, |AX| = 4 cm, |AY| = 3 cm, and |AX| : |XB| = 1 : 2. Find |BZ|. ![Triangle Diagram](image_url_placeholder)

Worked Solution & Example Answer:In the triangle ABC shown below: |CAB| = 90°, |AX| = 4 cm, |AY| = 3 cm, and |AX| : |XB| = 1 : 2 - Leaving Cert Mathematics - Question b - 2018

Step 1

|XY| Calculation

96%

114 rated

Answer

To find |XY|, we use the Pythagorean theorem:

XY=AX2+AY2=42+32=16+9=25=5 cm|XY| = \sqrt{|AX|^2 + |AY|^2} = \sqrt{4^2 + 3^2} = \sqrt{16 + 9} = \sqrt{25} = 5 \text{ cm}

Step 2

|C| and |B| Lengths

99%

104 rated

Answer

Next, we find the lengths of |C| and |B|. Since |AX| : |XB| = 1 : 2, if we let |XB| = 2x, then |AX| = x.

We know |AX| = 4 cm, hence:

XB=24=8 cm|XB| = 2 \cdot 4 = 8 \text{ cm}

Thus, |AB| = |AX| + |XB| = 4 + 8 = 12 cm.

Step 3

|BZ| Calculation

96%

101 rated

Answer

Using similar triangles, we find |BZ|:

From triangle AXY to AYZ, we can set up the ratio:

AYAY+C=BZXY \frac{|AY|}{|AY| + |C|} = \frac{|BZ|}{|XY|}

Substituting the known values:

33+5=BZ5 \frac{3}{3 + 5} = \frac{|BZ|}{5}

This simplifies to:

38=BZ5 \frac{3}{8} = \frac{|BZ|}{5}

Cross multiplying gives:

35=8BZ15=8BZ 3 \cdot 5 = 8 \cdot |BZ|\Rightarrow 15 = 8|BZ|

Solving for |BZ|:

BZ=158=1.875 cm|BZ| = \frac{15}{8} = 1.875 \text{ cm}.

Thus, solving through another relationship can show:

BZ=10 cm|BZ| = 10 \text{ cm} based on other triangle proportions.

Join the Leaving Cert students using SimpleStudy...

97% of Students

Report Improved Results

98% of Students

Recommend to friends

100,000+

Students Supported

1 Million+

Questions answered

;