مساحة المثلث بدلالة طولي أي ضلعين فيه وجيب الزاوية المحصورة بينهما

رسالة الخطأ

Drupal\Core\Field\BaseFieldDefinition->getDefaultValue(Object) (Line: 169)
Drupal\Core\Field\FieldItemList->applyDefaultValue() (Line: 137)
Drupal\Core\Entity\ContentEntityStorageBase->initFieldValues(Object, Array) (Line: 79)
Drupal\Core\Entity\ContentEntityStorageBase->doCreate(Array) (Line: 184)
Drupal\Core\Entity\EntityStorageBase->create(Array) (Line: 195)
Drupal\votingapi_widgets\Plugin\VotingApiWidgetBase->getEntityForVoting('node', 'video_lesson', '5468', 'vote', 'field_lesson_rate') (Line: 128)
Drupal\votingapi_widgets\Plugin\VotingApiWidgetBase->getForm('node', 'video_lesson', '5468', 'vote', 'field_lesson_rate', Array) (Line: 31)
Drupal\votingapi_widgets\Plugin\votingapi_widget\FiveStarWidget->buildForm('node', 'video_lesson', '5468', 'vote', 'field_lesson_rate', Array) (Line: 35)
Drupal\votingapi_widgets\VotingApiLoader->buildForm('fivestar', 'node', 'video_lesson', '5468', 'vote', 'field_lesson_rate', 'a:5:{s:5:"style";s:9:"css-stars";s:8:"readonly";i:0;s:12:"show_results";i:0;s:13:"show_own_vote";i:0;s:6:"values";a:0:{}}')
call_user_func_array(Array, Array) (Line: 358)
Drupal\Core\Render\Renderer->doRender(Array, 1) (Line: 195)
Drupal\Core\Render\Renderer->render(Array, 1) (Line: 151)
Drupal\Core\Render\Renderer->Drupal\Core\Render\{closure}() (Line: 582)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 152)
Drupal\Core\Render\Renderer->renderPlain(Array) (Line: 166)
Drupal\Core\Render\Renderer->renderPlaceholder('', Array) (Line: 667)
Drupal\Core\Render\Renderer->replacePlaceholders(Array) (Line: 552)
Drupal\Core\Render\Renderer->doRender(Array, 1) (Line: 195)
Drupal\Core\Render\Renderer->render(Array, 1) (Line: 139)
Drupal\Core\Render\Renderer->Drupal\Core\Render\{closure}() (Line: 582)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 140)
Drupal\Core\Render\Renderer->renderRoot(Array) (Line: 258)
Drupal\Core\Render\HtmlResponseAttachmentsProcessor->renderPlaceholders(Object) (Line: 131)
Drupal\Core\Render\HtmlResponseAttachmentsProcessor->processAttachments(Object) (Line: 45)
Drupal\Core\EventSubscriber\HtmlResponseSubscriber->onRespond(Object, 'kernel.response', Object)
call_user_func(Array, Object, 'kernel.response', Object) (Line: 111)
Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch('kernel.response', Object) (Line: 191)
Symfony\Component\HttpKernel\HttpKernel->filterResponse(Object, Object, 1) (Line: 173)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 68)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 57)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 184)
Drupal\page_cache\StackMiddleware\PageCache->fetch(Object, 1, 1) (Line: 121)
Drupal\page_cache\StackMiddleware\PageCache->lookup(Object, 1, 1) (Line: 75)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 52)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 666)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)