Deltoid Geometry: Calculate OC Given AO = 3cm and Triangle Ratio 1:3

Question

Shown below is the deltoid ABCD.

The ratio between triangle ABD and triangle BDC is 1:3.

Given in cm:

AO = 3

Calculate side OC.

333AAABBBCCCDDDOOO

Video Solution

Solution Steps

00:00 Calculate OC
00:03 We'll use the formula for calculating the area of triangle ABD
00:13 We'll do the same for triangle BDC
00:20 We'll substitute these formulas in the triangles' ratio according to the given data
00:30 We'll simplify what we can
00:41 Size of AO according to the given data
00:46 We'll substitute the value of AO and solve for CO
00:51 And this is the solution to the question

Step-by-Step Solution

To solve for OCOC, follow these steps:

  • Step 1: Establish the area relationships. Given Area of ABDArea of BDC=13 \frac{\text{Area of } \triangle ABD}{\text{Area of } \triangle BDC} = \frac{1}{3} , these areas are proportional to segments AOAO and OCOC under height implications.
  • Step 2: Apply the area ratio property. Since areas are directly proportional to their corresponding triangle heights from a shared vertex, AOOC=13 \frac{AO}{OC} = \frac{1}{3} .
  • Step 3: Algebraically solve for OCOC. Expressing proportions, 13×OC=AO\frac{1}{3} \times OC = AO, gives OC=3×3OC = 3 \times 3.
  • Step 4: Solve: OC=9cmOC = 9 \, \text{cm}.

The accurate solution to the problem is OC=9cm OC = 9 \, \text{cm} .

Answer

9 cm