DRAW AN ISOSCELES TRIANGLE WHOSE BASE IS 7 CM AND THE SUM OF TWO ANGLES AT BASE IS 140.
PLEASE SOLVE THIS PROBLEM ..
I AM MARK AS BRAINLIST........
Answers
Answer:
Step-by-step explanation:
A triangle which has two of its sides equal in length.
Try this Drag the orange dots on each vertex to reshape the triangle. Notice it always remains an isosceles triangle, the sides AB and AC always remain equal in length
The word isosceles is pronounced "eye-sos-ell-ease" with the emphasis on the 'sos'. It is any triangle that has two sides the same length.
If all three sides are the same length it is called an equilateral triangle. Obviously all equilateral triangles also have all the properties of an isosceles triangle.
Properties
The unequal side of an isosceles triangle is usually referred to as the 'base' of the triangle.
The base angles of an isosceles triangle are always equal. In the figure above, the angles ∠ABC and ∠ACB are always the same
When the 3rd angle is a right angle, it is called a "right isosceles triangle".
The altitude is a perpendicular distance from the base to the topmost vertex.
Constructing an Isosceles Triangle
It is possible to construct an isosceles triangle of given dimensions using just a compass and straightedge. See these three constructions:
Isosceles triangle, given base and side
Isosceles triangle, given base and altitude
Isosceles triangle, given leg and apex angle
Solving an isosceles triangle
The base, leg or altitude of an isosceles triangle can be found if you know the other two. A perpendicular bisector of the base forms an altitude of the triangle as shown on the right. This forms two congruent right triangles that can be solved using Pythagoras' Theorem as shown below.
Finding the base
To find the base given the leg and altitude, use the formula:
Base = 2 √ L 2 − A 2
where:
L is the length of a leg
A is the altitude
Finding the leg
To find the leg length given the base and altitude, use the formula:
Leg = √ A 2 +
B
2
2
where:
B is the length of the base
A is the altitude
Altitude
To find the altitude given the base and leg, use the formula:
Altitude = √ L 2 −
B
2
2
where:
L is the length of a leg
B is the base
Interior angles
apex angle of isosceles triangleIf you are given one interior angle of an isosceles triangle you can find the other two.
For example, We are given the angle at the apex as shown on the right of 40°. We know that the interior angles of all triangles add to 180°. So the two base angles must add up to 180-40, or 140°. Since the two base angles are congruent (same measure), they are each 70°.
base angle of isosceles triangleIf we are given a base angle of say 45°, we know the base angles are congruent (same measure) and the interior angles of any triangle always add to 180°. So the apex angle must be 180-45-45 or 90°.
Other triangle topics
General
Triangle definition
Hypotenuse
Triangle interior angles
Triangle exterior angles
Triangle exterior angle theorem
Pythagorean Theorem
Proof of the Pythagorean Theorem
Pythagorean triples
Triangle circumcircle
Triangle incircle
Triangle medians
Triangle altitudes
Midsegment of a triangle
Triangle inequality
Side / angle relationship
Perimeter / Area
Perimeter of a triangle
Area of a triangle
Heron's formula
Area of an equilateral triangle
Area by the "side angle side" method
Area of a triangle with fixed perimeter
Triangle types
Right triangle
Isosceles triangle
Scalene triangle
Equilateral triangle
Equiangular triangle
Obtuse triangle
Acute triangle
3-4-5 triangle
30-60-90 triangle
45-45-90 triangle
Triangle centers
Answer:
construction:
1) Draw a base AB =7cm
2)mark the angle 140 at both sides A and B.
3)now make a line through A and B
4)join the both lines.
5) Mark point C where the both lines meet.
than you will get the required triangle.
Step-by-step explanation:
hope it helps .
Mark as brainlist.