Mathematics Questions and Answers – Pair of Angles


This set of Mathematics Multiple Choice Questions & Answers (MCQs) focuses on “Pair of Angles”.

1. If a ray stands on a line, then the sum of two adjacent angle is 180°.
a) True
b) False
View Answer

Answer: a
Explanation: As shown in below diagram, we can see that ray OQ stands on line PQ.

We know that angle formed by a line is 180° so angle formed by the line PQ is 180°.
We also know that for two adjacent angles ∠POR and ∠ROQ,
∠POR + ∠ROQ = ∠POQ = angle formed by line PQ = 180°.

2. From the given diagram, if ∠SOQ : ∠ROQ = 2 : 3, then what are the values of angles ∠SOQ and ∠ROQ?

a) 54° and 36°
b) 40° and 60°
c) 72° and 48°
d) 72° and 108°
View Answer

Answer: d
Explanation: We know from axiom 6.1 that if a ray stands on a line, then the sum of two adjacent angle is 180°.
Here, ∠SOQ and ∠ROQ are two adjacent angles.
Hence, ∠SOQ + ∠ROQ = 180° and ∠SOQ : ∠ROQ = 2 : 3
Therefore, ∠SOQ = 2/(2+3) * 180
= 2/5 * 180
= 72°
∠ROQ = 3/(2+3) * 180
= 3/5 * 180
= 108°.

Sanfoundry Global Education & Learning Series – Mathematics – Class 9.


To practice all areas of Mathematics, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Manish Bhojasia - Founder & CTO at Sanfoundry
Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He is Linux Kernel Developer & SAN Architect and is passionate about competency developments in these areas. He lives in Bangalore and delivers focused training sessions to IT professionals in Linux Kernel, Linux Debugging, Linux Device Drivers, Linux Networking, Linux Storage, Advanced C Programming, SAN Storage Technologies, SCSI Internals & Storage Protocols such as iSCSI & Fiber Channel. Stay connected with him @ LinkedIn | Youtube | Instagram | Facebook | Twitter