Triangle and Its Types

In an obtuse angle $∆\mathrm{ABC}$, $O$ is orthocenter, $\angle BOC$ is $54°$, then find the value of $\angle BAC$.

In the given figure,$\mathrm{L}$ is any point on the bisector of the acute $\angle \mathrm{ABC}$and the line $\mathrm{ML}$is parallel to$\mathrm{BC}.$ Which one of the following is correct?

The sides of a triangle are $6\mathrm{cm}, 11\mathrm{cm}$ and $15\mathrm{cm}.$ The radius of its incircle is:

The length of side $AB$ and side $BC$ of a scalene triangle $ABC$ are $12 \mathrm{cm}$ and $8 \mathrm{cm}$ respectively. The measure of angle $C$ is $59°$. Find the length of side $AC$

What type of triangle is this?

Sides of a triangle are $8 \mathrm{cm}, 8 \mathrm{cm} \& 8 \mathrm{cm}$. Find the perimeter of the triangle.

Sides of a triangle are $7 \mathrm{cm}, 5 \mathrm{cm} \& 6 \mathrm{cm}$. Find the perimeter of the triangle.

Sides of a triangle are $3 \mathrm{cm}, 4 \mathrm{cm} \& 5 \mathrm{cm}$. Find the perimeter of the triangle.

The angles adjacent to side $DE$ are

What is the area of a triangle whose sides are $7 \mathrm{cm}, 24 \mathrm{cm} \mathrm{and} 25 \mathrm{cm}?$

The angles of a triangle are in the ratio of $3 : 4 : 8$. The triangle is:

The angles of a triangle are in the ratio $3 : 4 : 5$. The triangle is:

An acute angled triangle has only one acute angle.

In the adjoining figure, $\angle ABC=110°,\angle EDC=100$ and $AB\parallel DE$ then $\angle BCD$ is equal to 

In the trapezium $ABCD$, $BC\parallel AD, \angle B=90°, AB=BC$and $\angle ACD=20°$. If $\angle FCD=\theta$, then value of $\theta$ is

$\mathrm{D}$ is a point on the side $\mathrm{BC}$ of a triangle ABC such that $\mathrm{AD}\perp \mathrm{BC}$ . E is a point on AD for which $\mathrm{AE} : \mathrm{ED}$$=5:1$. If$\angle \mathrm{BAD}=30°$ and $t\mathrm{an}\left(\angle \mathrm{ACB}\right)=6\times \tan \left(\angle \mathrm{DBE}\right)$, then find $\angle \mathrm{ACB}$?

$16$ lines form $8$ equilateral triangles as shown in the figure.

Remove four lines from the above figure to form four equilateral triangles.

In case of an acute angled triangle, its orthocentre lies:

In the given figure if PQ||RS, then find out the value of \( \angle \) PSR:

If one of the acute angles of a right-angled triangle is $55°$, what is the measure of the other acute angle?