1. No.
2. No.
3. Yes.
4. No.
A straight line is 180°, so you can do:
109 + ? = 180 (? is the top angle of the triangle)
? = 71°
Because the triangle is an isosceles triangle, the other angle is 71° too.
71 + 71 + ? = 180
? = 38
You subtract 38 with 90 to find the other angle.
90 - 38 = 52°
To find ∠2 you subtract 52 with 180.
180 - 52 = 128
∠2 = 128
128 = 11x + 18
110 = 11x
10 = x
You can use estimation to find the product of two decimals by rounding both the decimal’s so the nearest tenth or tens place (depending on how long it is) and then multiplying the decimals.
for example, if you had 4.6 and 8.9, you have to round the 4.6 and 8.9. you round the 4.6 up to 5 because the 6 bumps the 4 up to 5) and then round 8.9 to 9 (because the 9 bumps the 8 up to 8.) then, multiply 5 and 9 and you get 45!