Download App

Lines and Angles — Maths STD 9 — Question

Gujarat BoardEnglish MediumSTD 9MathsLines and Angles1 Mark
MCQ
Two lines $AB$ and $CD$ intersect at $O$. If $\angle\text{AOC}+\angle\text{COB}+\angle\text{BOD}=270^\circ,$ then $\angle\text{AOC}=$
  • A
    $180^\circ$
  • B
    $70^\circ$
  • C
    $80^\circ$
  • ✓
    $90^\circ$
✓

Answer

Correct option: D.
$90^\circ$
Given that,
$AB$ and $CD$ intersect at $O$
$\angle\text{AOC}+\angle\text{COB}+\angle\text{BOD}=270^\circ\text{(i)}$
$\angle​\text{COB}+\angle\text{BOD}=180^\circ$ (Linear pair) $(ii)$
Using $(ii)$ in $(i)$, we get
$\angle​\text{AOC}+180^\circ=270^\circ$
$​\text{AOC}=90^\circ.$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q" from Lines and Angles→Lines and Angles — all question types→Maths STD 9 question papers→Gujarat Board STD 9 question papers→Gujarat Board question paper generator→

Similar questions

Write the correct answer in the following: Thales belongs to the country:
→
Two lines are said to be ________ if they intersect at right angles.
→
$2\sqrt{3}+\sqrt{3}$ is equal to:
→
The lengths of the diagonals of a rhombus are $16\ cm$ and $12\ cm$. The length of each side of the rhombus is:
→
The sum of the length, breadth and depth of a cuboid is $19\ cm$ and its diagonal is $5\sqrt{5}\text{cm}.$ Its surface area is:
→
The perpendicular distance of the point $P(-2, -3)$ from the $y-$axis is:
→
The cost of digging a pit of dimensions $4.5m × 2.5m × 2.5m$ at the rate of $₹ 20$ per cubic metre is:
→
$\frac{1}{\sqrt9-\sqrt8}$ is equal to:
→
The sides of a triangular field are $325m, 300m$ and $125m.$ Its area is:
→
The area of the the triangle having sides $1m, 2m$ and $2m$ is:
→