Area of an Obtuse Triangle

Q.

A floral design on a floor is made up of $16$ tiles which are triangular, the sides of the triangle being $9$ cm, $28$ cm and $35$ cm. Find the cost of polishing the tiles at the rate of $50p$ per cm²

Q.

If the side of an equilateral triangle is $8\text{cm}$, then find its area.

Q.

$\mathrm{B},\mathrm{C},\mathrm{H}$Sides of a triangular field are $15m,16m$and $17m.$ With the three corners of the field a cow, a buffalo and a horse are tied separately with ropes of length $7m$each to graze in the field. Find the area of the field which cannot be grazed by the three animals.

Q.
For an obtuse triangle $PQR$ as shown in the diagram above, if $PA=8$ units and area of $\Delta PQR=64$ sq. units, then $QR$ equals

1. 16

Q.

An umbrella is made by stitching $ 10$ triangular pieces of cloth of two different colors (see Fig.12.16), each piece measuring $ 20 cm, 50 cm$ and $ 50 cm$. How much cloth of each color is required for the umbrella?

Q.

Find the cost of laying grass in a triangular field of sides $50\mathrm{m}$, $65\mathrm{m}$ and $65\mathrm{m}$ at the rate of $₹7$ per ${\mathrm{m}}^2$

Q. $\Delta ABC$ is an obtuse triangle and $AC=6$ units and $CP=3$ units, then the area of $\Delta ABC=$.

1. $12$ sq. units
2. $24$ sq. units
3. $12$ sq. units

Q.
The area(in sq. units) of the trianlge $PQR$ as shown in the diagram is

1. $7.5$ sq. units
2. $15$ sq. units
3. $10$ sq. units

Q. Find the base of an obtuse angle triangle of area 24.5 ${\text{m}}^2,$ if the height of a triangle is 7 m.

1. 14 m
2. 21 m
3. 7 m
4. 10 m

Q. Find the area of an obtuse angle triangle ABC as shown in the figure.

1. $28{\text{unit}}^2$
2. $28\text{unit}$
3. $35{\text{unit}}^2$
4. $56{\text{unit}}^2$

Q. Find the ratio of area to the perimeter of an obtuse angle triangle as shown in the figure below.

1. $\frac{24}{25}$
2. $\frac{24}{25}unit$
3. $\frac{25}{24}unit$
4. $\frac{30}{25}$

Q. John has cut a piece of paper into an obtuse triangle. The area of an obtuse angle triangle is $48{\text{ft}}^2$ and the base of a triangle is 12 ft. The height of the triangular piece of paper is__

1. 2 ft
2. 6 ft
3. 10 ft
4. 8 ft

Q. Find the area of an obtuse angle triangle ABC as shown in the figure.

1. $\frac{ab}{2}{\text{unit}}^2$
2. $\frac{a(b+d)}{2}{\text{unit}}^2$
3. $\frac{ab}{2}\text{unit}$
4. $\frac{abc}{2}{\text{unit}}^2$

Q. For the given triangle above, its $Area=\frac{1}{2}\times (b+c)\times d$.

1. False
2. True