Answer:the answer is a
Step-by-step explanation:
Based on the CPCTC theorem, the congruences that are true about the given triangles are:
B. ∠K ≅ ∠S
C. KL ≅ ST
D. JK ≅ RS
<h3>What is the CPCTC Theorem?</h3>
According to the CPCTC theorem states that if two triangles are congruent to each other, then, all their corresponding parts will be congruent to each other.
Given that triangles JKL and RST are congruent to each other, therefore:
∠J ≅ ∠R
∠K ≅ ∠S
∠L ≅ ∠T
JK ≅ RS
KL ≅ ST
JL ≅ RT
Therefore, the congruences that would be true by CPCTC are:
B. ∠K ≅ ∠S
C. KL ≅ ST
D. JK ≅ RS
Learn more about the CPCTC theorem on:
brainly.com/question/14706064
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Answer:
m<ABC = 71°
Step-by-step explanation:
Given:
m<BCA = 71°
x = 31 cm
y = 50 cm
Required:
m<ABC
Solution:
First, find AB, using Cosine Rule:
AB² = x² + y² - 2xy*Cos m<ABC
Plug in the values
AB² = 31² + 50² - 2(31)(50)*cos 71
AB² = 3,461 - 1,009.26128
AB² = 2,451.73872
AB = √2,451.73872
AB = 49.5150353 ≈ 50 cm
✔️Since AB ≈ 50 cm, and AC is also 50 cm, it means the triangle is an isosceles triangle.
Therefore, the base angles of ∆ABC, <ABC and <BCA, would be congruent.
Therefore,
m<BCA = m<ABC = 71°
m<ABC = 71°
