Question

In ∆PQR, measure of p =80 0 and Q=65°. Find the measure of the exterior angle at vertex R.
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Answer 1

$\huge\mathfrak\pink{helloo}$

$\huge\mathfrak\red{ANSWER}$By using the theorem,If two sides of a triangle are equal then the opposite angles to the sides are equal.

⇒ If PQ=PR then ∠Q=∠R

In △PQR,

⇒∠P+∠Q+∠R=180 ∘

 ⇒∠P+∠Q+∠R=180  ∘

 since ∠Q=∠R=65  ∘

(given)

⇒∠P+2×65  ∘ =180  ∘

 ⇒∠P=180  ∘ −130  ∘

=50  ∘

 ∴∠P=50  ∘

hope it helps u

Answer 2

$\huge{\blue{\bold{\boxed{\ulcorner{\star\:Answer\: \star}\urcorner}}}}$

By using the theorem,If two sides of a triangle are equal then the opposite angles to the sides are equal.

⇒ If PQ=PR then ∠Q=∠R

In △PQR,

⇒∠P+∠Q+∠R=180 ∘

 ⇒∠P+∠Q+∠R=180  ∘

 since ∠Q=∠R=65  ∘

(given)