Question

ET

en figure, if AOB is a line then find the
measure of ZBOC, ZCOD and ZDOA.
A
D
5y
3y
12y
B

Answer 1

In the given figure, if AOB is a straight line, we can find the measures of angles ZBOC, ZCOD, and ZDOA.

Since AOB is a straight line, the sum of the angles around point O equals 180 degrees.

1. ZBOC + ZCOD + ZDOA = 180°

We are given that angle ZBOC is 5y, angle ZCOD is 3y, and angle ZDOA is 12y.

1. 5y + 3y + 12y = 180°

Combine the terms on the left side:

1. 20y = 180°

Now solve for y:

1. 
   `y = (180\°)/(20) = 9\°`

Now that we know the value of y, we can find the measures of the individual angles:

1. ZBOC = 5y = 5 × 9° = 45°
2. ZCOD = 3y = 3 × 9° = 27°
3. ZDOA = 12y = 12 × 9° = 108°

So, in the given figure, if AOB is a straight line, the measures of angles are:

• ZBOC = 45°
• ZCOD = 27°
• ZDOA = 108°

Answer 2

Here we will learn about co-interior angles including how to recognise co-interior angles, and apply this understanding to solve problems.

There are also angles in parallel lines worksheets based on Edexcel, AQA and OCR exam questions, along with further guidance on where to go next if you’re still stuck.