Sagot :
The measure of angle R in triangle RST is 40°.
Given that triangle RST is isosceles triangle,
that means two of its angles are equal.
Also the measure of angle T is 100°
since no other angle can be equal to 100° because in this case the sum of the angles will be more than 180°
so the other two angles R and S are equal.
⇒ ∠R + ∠S + ∠T = 180°
∠R + ∠R + 100° = 180°
2∠R = 180 - 100
∠R = [tex]\frac{80}{2}[/tex]
∠R = 40°.
Therefore measure of angle R in triangle RST is 40°.
An Isosceles triangle is a triangle that has any two sides equal in length and angles opposite to equal sides are equal in measure. An Isosceles triangle is a triangle which has two congruent sides. And in isosceles triangle if the two sides of a triangle are congruent, then the angle opposite to them are also congruent.
Given question is incomplete. Complete question is:
If the measure of ∠T is 100°. What is the measure of angle R in isosceles triangle RST?
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