Question

in an isosceles triangle the base angles are equal the vertex angle is 40 degree what are the base angles of the triangle

Answer 1

Vertex angle=40°

Sum of three angles of a triangle

=180°

A.T.Q

x+x+40°=180°

2x=180°-40°

2x=140°

x=140/2

x=70°

Base angles=70°,70°

Vertex angle=40°

Answer 2

Given Question:-

In an isosceles triangle , The base angles are equal . The vertex angle is 40 degree. What are the base angles of the triangle?

To Find:-

• Base Angle of The Triangle , If the vertex angle is 40°

Remember:-

The Sum of three angle $\triangle$ is Always 180°

Explanation:-

Here, We have Given the Measure of only 1 angle that is 40° And the Question says to find the measure of other two angles of An isoceles Triangle .

Isoceles Triangle $\triangle$ Means A triangle which have only 2 sides are Equal . To Find the Other two angles! We take those 2 Angles as " b " ! After Substituting Those Angles by method we'll Get the Answer 70°

Solution:-

The measure of those 2 angles in $\triangle$ are 70° Each.

Step By Step Explanation:-

$\begin{gathered}:\implies\sf {Let \: the \: base \: angle \: = \: b}\\\\\:\:\::\implies \sf{Vertex\: Angle \: = 40°}\\ \\\\ \: :\implies\sf{ Sum~of ~the ~ angles ~ of ~ a ~ \triangle = ~ 180° }\end{gathered}$

According to the Question:-

$\begin{gathered} :\implies\sf{ b + b + 40° = 180°}\\\\ :\implies\sf{2b = 180° - 40°}\\\\\: :\implies\sf{2b = 140}\\\\\: :\implies\sf{ b = \dfrac{\cancel{140}^{70}}{\cancel{2_1}}}\\\\\: :\implies{\underline {\boxed{\frak{\pink{ b = 70°}}}}}\\\\\\\:\end{gathered}$

$\dag\: \: \sf{\underline {The ~~ Base ~ Angle ~ are ~ 70° each}}$