Answer:
(d) 60°
Step-by-step explanation:
<u>Theorems</u>
- Interior angles of a triangle sum to 180°
- Angles on a straight line sum to 180°
Therefore, the <u>exterior angle</u> of a triangle is <u>equal to the sum</u> of the <u>two non-adjacent interior angles</u> of the triangle.
⇒ (a + 20) + (a + 10) = (a + 90)
⇒ a + 20 + a + 10 = a + 90
⇒ 2a + 30 = a + 90
⇒ 2a + 30 - a = a + 90 - a
⇒ a + 30 = 90
⇒ a + 30 - 30 = 90 - 30
⇒ a = 60
Answer:6.54
Step-by-step explanation:please give me brainliest
Answer:
2 1/4 times
Step-by-step explanation:
A builder was building a fence. In the moring he worked 2/5 of an hour. In the afternoon he wirked for 9/10 of an hour. how many times as long in the morning did he work in the afternoon
Note that:
1 hour = 60 minutes
In the moring he worked 2/5 of an hour.
= 2/5 × 60 minutes
= 24 minutes
In the afternoon he worked for 9/10 of an hour
Hence:
9/10 × 60 minutes
= 54 minutes
How many times as long in the morning did he work in the afternoon?
This is calculated as number of minutes worked in the afternoon ÷ Number of minutes worked in the morning
= 54 minutes/24 minutes
= 2 6/24
= 2 1/4 times