Answer:
r = 1.9
Step-by-step explanation:
7r + 7 = 20.3
<u> - 7 - 7 </u>
7r = 13.3
divide by 7
r = 1.9
Answer:
Δ JKL is similar to Δ ABC ⇒ D
Step-by-step explanation:
Similar triangles have equal angles in measures
In ΔABC
∵ m∠A = 15°
∵ m∠B = 120
∵ The sum of the measures of the interior angles of a Δ is 180°
∴ m∠A + m∠B + m∠C = 180°
→ Substitute the measures of ∠A and ∠B
∵ 15 + 120 + m∠C = 180
→ Add the like terms in the left side
∴ 135 + m∠C = 180
→ Subtract 135 from both sides
∴ 135 - 135 + m∠C = 180 - 135
∴ m∠C = 45°
The similar Δ to ΔABC must have the same measures of angles
If triangles ABC and JKL are similar, then
m∠A must equal m∠J
m∠B must equal m∠K
m∠C must equal m∠L
∵ m∠J = 15°
∴ m∠A = m∠J
∵ m∠L = 45°
∴ m∠C = m∠L
∵ m∠J + m∠K + m∠L = 180°
→ Substitute the measures of ∠J and ∠L
∵ 15 + m∠K + 45 = 180
→ Add the like terms in the left side
∴ 60 + m∠K = 180
→ Subtract 60 from both sides
∴ 60 - 60 + m∠K = 180 - 60
∴ m∠K = 120°
∴ m∠B = m∠K
∴ Δ JKL is similar to Δ ABC
Answer:
2
Step-by-step explanation:
3 x 4 = 12 - 8 = 4 ÷ 2 = 2
Problem 215
Check out the attached image. Line up the letters ABC and CDE so the first set of letters are over the second set of letters. Order is important here. Note how A corresponds to C (second C), B corresponds to D, and (the first) C corresponds to E.
We have this mapping:
A <--> C
B <--> D
C <--> E
This means...
Angle BAC corresponds to Angle DCE (red angles)
Angle ABC corresponds to Angle CDE (blue angles)
Angle BCA corresponds to Angle DEC (green angles)
It also means...
Side BC corresponds to Side DE (red sides)
Side AC corresponds to Side CE (blue sides)
Side AB corresponds to Side CD (green sides)
Check out the attached image which I hope clears up any confusion you may have. Often I think it helps to represent stuff like this in a visual way.
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Problem 216
Answer: True
Since triangle ABC is congruent to triangle DEF, this means that side AB is congruent to side ED. These are corresponding sides. Since AB = 6, this means ED = 6 as well.